diff --git a/.prettierrc.js b/.prettierrc.js
index 6342f131a0..43f9b6671c 100644
--- a/.prettierrc.js
+++ b/.prettierrc.js
@@ -14,6 +14,12 @@ module.exports = {
   parser: 'flow',
   arrowParens: 'avoid',
   overrides: [
+    {
+      files: ['*.code-workspace'],
+      options: {
+        parser: 'json-stringify',
+      },
+    },
     {
       files: esNextPaths,
       options: {
diff --git a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
index 826b720300..e5a067018d 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
@@ -1668,6 +1668,15 @@ function lowerExpression(
       const left = lowerExpressionToTemporary(builder, leftPath);
       const right = lowerExpressionToTemporary(builder, expr.get("right"));
       const operator = expr.node.operator;
+      if (operator === "|>") {
+        builder.errors.push({
+          reason: `(BuildHIR::lowerExpression) Pipe operator not supported`,
+          severity: ErrorSeverity.Todo,
+          loc: leftPath.node.loc ?? null,
+          suggestions: null,
+        });
+        return { kind: "UnsupportedNode", node: exprNode, loc: exprLoc };
+      }
       return {
         kind: "BinaryExpression",
         operator,
@@ -1893,7 +1902,9 @@ function lowerExpression(
         );
       }
 
-      const operators: { [key: string]: t.BinaryExpression["operator"] } = {
+      const operators: {
+        [key: string]: Exclude<t.BinaryExpression["operator"], "|>">;
+      } = {
         "+=": "+",
         "-=": "-",
         "/=": "/",
@@ -2307,6 +2318,20 @@ function lowerExpression(
           });
           return { kind: "UnsupportedNode", node: expr.node, loc: exprLoc };
         }
+      } else if (expr.node.operator === "throw") {
+        builder.errors.push({
+          reason: `Throw expressions are not supported`,
+          severity: ErrorSeverity.InvalidJS,
+          loc: expr.node.loc ?? null,
+          suggestions: [
+            {
+              description: "Remove this line",
+              range: [expr.node.start!, expr.node.end!],
+              op: CompilerSuggestionOperation.Remove,
+            },
+          ],
+        });
+        return { kind: "UnsupportedNode", node: expr.node, loc: exprLoc };
       } else {
         return {
           kind: "UnaryExpression",
diff --git a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
index d544269869..2294335034 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
@@ -866,7 +866,7 @@ export type InstructionValue =
   | JSXText
   | {
       kind: "BinaryExpression";
-      operator: t.BinaryExpression["operator"];
+      operator: Exclude<t.BinaryExpression["operator"], "|>">;
       left: Place;
       right: Place;
       loc: SourceLocation;
@@ -881,7 +881,7 @@ export type InstructionValue =
   | MethodCall
   | {
       kind: "UnaryExpression";
-      operator: t.UnaryExpression["operator"];
+      operator: Exclude<t.UnaryExpression["operator"], "throw" | "delete">;
       value: Place;
       loc: SourceLocation;
     }
diff --git a/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts b/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
index 632e665723..beda6e4a20 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
@@ -856,7 +856,7 @@ export function mapTerminalSuccessors(
       const block = fn(terminal.block);
       const fallthrough = fn(terminal.fallthrough);
       return {
-        kind: "scope",
+        kind: terminal.kind,
         scope: terminal.scope,
         block,
         fallthrough,
diff --git a/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReferenceEffects.ts b/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReferenceEffects.ts
index 619d1d90ff..ee2ad1a7de 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReferenceEffects.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/InferReferenceEffects.ts
@@ -201,7 +201,7 @@ export default function inferReferenceEffects(
     let queuedState = queuedStates.get(blockId);
     if (queuedState != null) {
       // merge the queued states for this block
-      state = queuedState.merge(state) ?? state;
+      state = queuedState.merge(state) ?? queuedState;
       queuedStates.set(blockId, state);
     } else {
       /*
@@ -765,7 +765,7 @@ class InferenceState {
       result.values[id] = { kind, value: printMixedHIR(value) };
     }
     for (const [variable, values] of this.#variables) {
-      result.variables[variable] = [...values].map(identify);
+      result.variables[`$${variable}`] = [...values].map(identify);
     }
     return result;
   }
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.expect.md
new file mode 100644
index 0000000000..41271ffaf0
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.expect.md
@@ -0,0 +1,72 @@
+
+## Input
+
+```javascript
+import { mutate } from "shared-runtime";
+
+/**
+ * Fixture showing why `concat` needs to capture both the callee and rest args.
+ * Here, observe that arr1's values are captured into arr2.
+ *  - Later mutations of arr2 may write to values within arr1.
+ *  - Observe that it's technically valid to separately memoize the array arr1
+ *    itself.
+ */
+function Foo({ inputNum }) {
+  const arr1: Array<number | object> = [{ a: 1 }, {}];
+  const arr2 = arr1.concat([1, inputNum]);
+  mutate(arr2[0]);
+  return arr2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ inputNum: 2 }],
+  sequentialRenders: [{ inputNum: 2 }, { inputNum: 3 }],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { mutate } from "shared-runtime";
+
+/**
+ * Fixture showing why `concat` needs to capture both the callee and rest args.
+ * Here, observe that arr1's values are captured into arr2.
+ *  - Later mutations of arr2 may write to values within arr1.
+ *  - Observe that it's technically valid to separately memoize the array arr1
+ *    itself.
+ */
+function Foo(t0) {
+  const $ = _c(3);
+  const { inputNum } = t0;
+  let t1;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = [{ a: 1 }, {}];
+    $[0] = t1;
+  } else {
+    t1 = $[0];
+  }
+  const arr1 = t1;
+  let arr2;
+  if ($[1] !== inputNum) {
+    arr2 = arr1.concat([1, inputNum]);
+    mutate(arr2[0]);
+    $[1] = inputNum;
+    $[2] = arr2;
+  } else {
+    arr2 = $[2];
+  }
+  return arr2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ inputNum: 2 }],
+  sequentialRenders: [{ inputNum: 2 }, { inputNum: 3 }],
+};
+
+```
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.ts b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.ts
new file mode 100644
index 0000000000..f9b5ed619c
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-array-concat-should-capture.ts
@@ -0,0 +1,21 @@
+import { mutate } from "shared-runtime";
+
+/**
+ * Fixture showing why `concat` needs to capture both the callee and rest args.
+ * Here, observe that arr1's values are captured into arr2.
+ *  - Later mutations of arr2 may write to values within arr1.
+ *  - Observe that it's technically valid to separately memoize the array arr1
+ *    itself.
+ */
+function Foo({ inputNum }) {
+  const arr1: Array<number | object> = [{ a: 1 }, {}];
+  const arr2 = arr1.concat([1, inputNum]);
+  mutate(arr2[0]);
+  return arr2;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ inputNum: 2 }],
+  sequentialRenders: [{ inputNum: 2 }, { inputNum: 3 }],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.expect.md
deleted file mode 100644
index 1ce503e4af..0000000000
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.expect.md
+++ /dev/null
@@ -1,78 +0,0 @@
-
-## Input
-
-```javascript
-import { arrayPush } from "shared-runtime";
-
-/**
- * Evaluator error:
- *   Found differences in evaluator results
- *   Non-forget (expected):
- *   (kind: ok) [2]
- *   [2]
- *   Forget:
- *   (kind: ok) [2]
- *   [2,2]
- */
-function Foo(cond) {
-  let x = null;
-  if (cond) {
-    x = [];
-  } else {
-  }
-  // Here, x = phi(x$null, x$[]) does not receive the correct ValueKind
-  arrayPush(x, 2);
-
-  return x;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Foo,
-  params: [{ cond: true }],
-  sequentialRenders: [{ cond: true }, { cond: true }],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import { arrayPush } from "shared-runtime";
-
-/**
- * Evaluator error:
- *   Found differences in evaluator results
- *   Non-forget (expected):
- *   (kind: ok) [2]
- *   [2]
- *   Forget:
- *   (kind: ok) [2]
- *   [2,2]
- */
-function Foo(cond) {
-  const $ = _c(1);
-  let x = null;
-  if (cond) {
-    let t0;
-    if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-      t0 = [];
-      $[0] = t0;
-    } else {
-      t0 = $[0];
-    }
-    x = t0;
-  }
-
-  arrayPush(x, 2);
-  return x;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Foo,
-  params: [{ cond: true }],
-  sequentialRenders: [{ cond: true }, { cond: true }],
-};
-
-```
-      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.expect.md
new file mode 100644
index 0000000000..bef1d7b836
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.expect.md
@@ -0,0 +1,61 @@
+
+## Input
+
+```javascript
+import { arrayPush } from "shared-runtime";
+
+function Foo(cond) {
+  let x = null;
+  if (cond) {
+    x = [];
+  } else {
+  }
+  // Here, x = phi(x$null, x$[]) should receive a ValueKind of Mutable
+  arrayPush(x, 2);
+
+  return x;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ cond: true }],
+  sequentialRenders: [{ cond: true }, { cond: true }],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import { arrayPush } from "shared-runtime";
+
+function Foo(cond) {
+  const $ = _c(2);
+  let x;
+  if ($[0] !== cond) {
+    x = null;
+    if (cond) {
+      x = [];
+    }
+
+    arrayPush(x, 2);
+    $[0] = cond;
+    $[1] = x;
+  } else {
+    x = $[1];
+  }
+  return x;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [{ cond: true }],
+  sequentialRenders: [{ cond: true }, { cond: true }],
+};
+
+```
+      
+### Eval output
+(kind: ok) [2]
+[2]
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.ts b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.ts
similarity index 54%
rename from compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.ts
rename to compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.ts
index 6660f059ca..092791d586 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-phi-reference-effect.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/phi-reference-effects.ts
@@ -1,22 +1,12 @@
 import { arrayPush } from "shared-runtime";
 
-/**
- * Evaluator error:
- *   Found differences in evaluator results
- *   Non-forget (expected):
- *   (kind: ok) [2]
- *   [2]
- *   Forget:
- *   (kind: ok) [2]
- *   [2,2]
- */
 function Foo(cond) {
   let x = null;
   if (cond) {
     x = [];
   } else {
   }
-  // Here, x = phi(x$null, x$[]) does not receive the correct ValueKind
+  // Here, x = phi(x$null, x$[]) should receive a ValueKind of Mutable
   arrayPush(x, 2);
 
   return x;
diff --git a/compiler/packages/snap/src/SproutTodoFilter.ts b/compiler/packages/snap/src/SproutTodoFilter.ts
index c2581e7e57..30dd4f86ce 100644
--- a/compiler/packages/snap/src/SproutTodoFilter.ts
+++ b/compiler/packages/snap/src/SproutTodoFilter.ts
@@ -489,7 +489,7 @@ const skipFilter = new Set([
   "original-reactive-scopes-fork/bug-nonmutating-capture-in-unsplittable-memo-block",
   "original-reactive-scopes-fork/bug-hoisted-declaration-with-scope",
   "bug-codegen-inline-iife",
-  "bug-phi-reference-effect",
+  "bug-array-concat-should-capture",
 
   // 'react-compiler-runtime' not yet supported
   "flag-enable-emit-hook-guards",
diff --git a/compiler/packages/snap/src/sprout/shared-runtime.ts b/compiler/packages/snap/src/sprout/shared-runtime.ts
index 94fba22c04..7d4687218d 100644
--- a/compiler/packages/snap/src/sprout/shared-runtime.ts
+++ b/compiler/packages/snap/src/sprout/shared-runtime.ts
@@ -36,7 +36,7 @@ export const CONST_NUMBER2 = 2;
 export const CONST_TRUE = true;
 export const CONST_FALSE = false;
 
-export function initFbt() {
+export function initFbt(): void {
   const viewerContext: IntlViewerContext = {
     GENDER: IntlVariations.GENDER_UNKNOWN,
     locale: "en_US",
@@ -52,7 +52,7 @@ export function initFbt() {
 
 export function mutate(arg: any): void {
   // don't mutate primitive
-  if (typeof arg === null || typeof arg !== "object") {
+  if (arg == null || typeof arg !== "object") {
     return;
   }
 
@@ -80,7 +80,7 @@ export function mutateAndReturnNewValue<T>(arg: T): string {
 
 export function setProperty(arg: any, property: any): void {
   // don't mutate primitive
-  if (typeof arg === null || typeof arg !== "object") {
+  if (arg == null || typeof arg !== "object") {
     return arg;
   }
 
@@ -123,7 +123,7 @@ export function calculateExpensiveNumber(x: number): number {
 /**
  * Functions that do not mutate their parameters
  */
-export function shallowCopy(obj: Object): object {
+export function shallowCopy(obj: object): object {
   return Object.assign({}, obj);
 }
 
@@ -139,9 +139,11 @@ export function addOne(value: number): number {
   return value + 1;
 }
 
-// Alias console.log, as it is defined as a global and may have
-// different compiler handling than unknown functions
-export function print(...args: Array<unknown>) {
+/*
+ * Alias console.log, as it is defined as a global and may have
+ * different compiler handling than unknown functions
+ */
+export function print(...args: Array<unknown>): void {
   console.log(...args);
 }
 
@@ -153,7 +155,7 @@ export function throwErrorWithMessage(message: string): never {
   throw new Error(message);
 }
 
-export function throwInput(x: Object): never {
+export function throwInput(x: object): never {
   throw x;
 }
 
@@ -167,12 +169,12 @@ export function logValue<T>(value: T): void {
   console.log(value);
 }
 
-export function useHook(): Object {
+export function useHook(): object {
   return makeObject_Primitives();
 }
 
 const noAliasObject = Object.freeze({});
-export function useNoAlias(...args: Array<any>): object {
+export function useNoAlias(..._args: Array<any>): object {
   return noAliasObject;
 }
 
@@ -183,7 +185,7 @@ export function useIdentity<T>(arg: T): T {
 export function invoke<T extends Array<any>, ReturnType>(
   fn: (...input: T) => ReturnType,
   ...params: T
-) {
+): ReturnType {
   return fn(...params);
 }
 
@@ -191,7 +193,7 @@ export function conditionalInvoke<T extends Array<any>, ReturnType>(
   shouldInvoke: boolean,
   fn: (...input: T) => ReturnType,
   ...params: T
-) {
+): ReturnType | null {
   if (shouldInvoke) {
     return fn(...params);
   } else {
@@ -205,21 +207,25 @@ export function conditionalInvoke<T extends Array<any>, ReturnType>(
 export function Text(props: {
   value: string;
   children?: Array<React.ReactNode>;
-}) {
+}): React.ReactElement {
   return React.createElement("div", null, props.value, props.children);
 }
 
-export function StaticText1(props: { children?: Array<React.ReactNode> }) {
+export function StaticText1(props: {
+  children?: Array<React.ReactNode>;
+}): React.ReactElement {
   return React.createElement("div", null, "StaticText1", props.children);
 }
 
-export function StaticText2(props: { children?: Array<React.ReactNode> }) {
+export function StaticText2(props: {
+  children?: Array<React.ReactNode>;
+}): React.ReactElement {
   return React.createElement("div", null, "StaticText2", props.children);
 }
 
 export function RenderPropAsChild(props: {
   items: Array<() => React.ReactNode>;
-}) {
+}): React.ReactElement {
   return React.createElement(
     "div",
     null,
@@ -242,7 +248,7 @@ export function ValidateMemoization({
 }: {
   inputs: Array<any>;
   output: any;
-}) {
+}): React.ReactElement {
   "use no forget";
   const [previousInputs, setPreviousInputs] = React.useState(inputs);
   const [previousOutput, setPreviousOutput] = React.useState(output);
@@ -273,7 +279,7 @@ export function createHookWrapper<TProps, TRet>(
 }
 
 // helper functions
-export function toJSON(value: any, invokeFns: boolean = false) {
+export function toJSON(value: any, invokeFns: boolean = false): string {
   const seen = new Map();
 
   return JSON.stringify(value, (_key: string, val: any) => {
@@ -319,7 +325,7 @@ export const ObjectWithHooks = {
   },
 };
 
-export function useFragment(...args: Array<any>): Object {
+export function useFragment(..._args: Array<any>): object {
   return {
     a: [1, 2, 3],
     b: { c: { d: 4 } },
diff --git a/fixtures/flight-esm/yarn.lock b/fixtures/flight-esm/yarn.lock
index a00d5c244d..8d336e5194 100644
--- a/fixtures/flight-esm/yarn.lock
+++ b/fixtures/flight-esm/yarn.lock
@@ -79,11 +79,11 @@ brace-expansion@^1.1.7:
     concat-map "0.0.1"
 
 braces@~3.0.2:
-  version "3.0.2"
-  resolved "https://registry.yarnpkg.com/braces/-/braces-3.0.2.tgz#3454e1a462ee8d599e236df336cd9ea4f8afe107"
-  integrity sha512-b8um+L1RzM3WDSzvhm6gIz1yfTbBt6YTlcEKAvsmqCZZFw46z626lVj9j1yEPW33H5H+lBQpZMP1k8l+78Ha0A==
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/braces/-/braces-3.0.3.tgz#490332f40919452272d55a8480adc0c441358789"
+  integrity sha512-yQbXgO/OSZVD2IsiLlro+7Hf6Q18EJrKSEsdoMzKePKXct3gvD8oLcOQdIzGupr5Fj+EDe8gO/lxc1BzfMpxvA==
   dependencies:
-    fill-range "^7.0.1"
+    fill-range "^7.1.1"
 
 browserslist@^4.18.1:
   version "4.21.7"
@@ -265,10 +265,10 @@ escalade@^3.1.1:
   resolved "https://registry.yarnpkg.com/escalade/-/escalade-3.1.1.tgz#d8cfdc7000965c5a0174b4a82eaa5c0552742e40"
   integrity sha512-k0er2gUkLf8O0zKJiAhmkTnJlTvINGv7ygDNPbeIsX/TJjGJZHuh9B2UxbsaEkmlEo9MfhrSzmhIlhRlI2GXnw==
 
-fill-range@^7.0.1:
-  version "7.0.1"
-  resolved "https://registry.yarnpkg.com/fill-range/-/fill-range-7.0.1.tgz#1919a6a7c75fe38b2c7c77e5198535da9acdda40"
-  integrity sha512-qOo9F+dMUmC2Lcb4BbVvnKJxTPjCm+RRpe4gDuGrzkL7mEVl/djYSu2OdQ2Pa302N4oqkSg9ir6jaLWJ2USVpQ==
+fill-range@^7.1.1:
+  version "7.1.1"
+  resolved "https://registry.yarnpkg.com/fill-range/-/fill-range-7.1.1.tgz#44265d3cac07e3ea7dc247516380643754a05292"
+  integrity sha512-YsGpe3WHLK8ZYi4tWDg2Jy3ebRz2rXowDxnld4bkQB00cc/1Zw9AWnC0i9ztDJitivtQvaI9KaLyKrc+hBW0yg==
   dependencies:
     to-regex-range "^5.0.1"
 
diff --git a/packages/react-devtools-core/src/standalone.js b/packages/react-devtools-core/src/standalone.js
index e4e4ada1c3..541efa0d37 100644
--- a/packages/react-devtools-core/src/standalone.js
+++ b/packages/react-devtools-core/src/standalone.js
@@ -280,6 +280,7 @@ function initialize(socket: WebSocket) {
   store = new Store(bridge, {
     checkBridgeProtocolCompatibility: true,
     supportsTraceUpdates: true,
+    supportsClickToInspect: true,
   });
 
   log('Connected');
diff --git a/packages/react-devtools-extensions/src/main/index.js b/packages/react-devtools-extensions/src/main/index.js
index e1db3d5055..5422567db7 100644
--- a/packages/react-devtools-extensions/src/main/index.js
+++ b/packages/react-devtools-extensions/src/main/index.js
@@ -97,7 +97,8 @@ function createBridgeAndStore() {
     // At this time, the timeline can only parse Chrome performance profiles.
     supportsTimeline: __IS_CHROME__,
     supportsTraceUpdates: true,
-    supportsNativeInspection: true,
+    supportsInspectMatchingDOMElement: true,
+    supportsClickToInspect: true,
   });
 
   if (!isProfiling) {
diff --git a/packages/react-devtools-fusebox/src/frontend.js b/packages/react-devtools-fusebox/src/frontend.js
index 976b8693d3..d55241fec7 100644
--- a/packages/react-devtools-fusebox/src/frontend.js
+++ b/packages/react-devtools-fusebox/src/frontend.js
@@ -37,6 +37,7 @@ export function createStore(bridge: FrontendBridge, config?: Config): Store {
   return new Store(bridge, {
     checkBridgeProtocolCompatibility: true,
     supportsTraceUpdates: true,
+    supportsClickToInspect: true,
     ...config,
   });
 }
diff --git a/packages/react-devtools-shared/src/devtools/store.js b/packages/react-devtools-shared/src/devtools/store.js
index 408151dcdb..ef6f720346 100644
--- a/packages/react-devtools-shared/src/devtools/store.js
+++ b/packages/react-devtools-shared/src/devtools/store.js
@@ -71,7 +71,8 @@ type ErrorAndWarningTuples = Array<{id: number, index: number}>;
 export type Config = {
   checkBridgeProtocolCompatibility?: boolean,
   isProfiling?: boolean,
-  supportsNativeInspection?: boolean,
+  supportsInspectMatchingDOMElement?: boolean,
+  supportsClickToInspect?: boolean,
   supportsReloadAndProfile?: boolean,
   supportsTimeline?: boolean,
   supportsTraceUpdates?: boolean,
@@ -172,7 +173,8 @@ export default class Store extends EventEmitter<{
   _rootIDToRendererID: Map<number, number> = new Map();
 
   // These options may be initially set by a configuration option when constructing the Store.
-  _supportsNativeInspection: boolean = false;
+  _supportsInspectMatchingDOMElement: boolean = false;
+  _supportsClickToInspect: boolean = false;
   _supportsReloadAndProfile: boolean = false;
   _supportsTimeline: boolean = false;
   _supportsTraceUpdates: boolean = false;
@@ -211,13 +213,17 @@ export default class Store extends EventEmitter<{
       isProfiling = config.isProfiling === true;
 
       const {
-        supportsNativeInspection,
+        supportsInspectMatchingDOMElement,
+        supportsClickToInspect,
         supportsReloadAndProfile,
         supportsTimeline,
         supportsTraceUpdates,
       } = config;
-      if (supportsNativeInspection) {
-        this._supportsNativeInspection = true;
+      if (supportsInspectMatchingDOMElement) {
+        this._supportsInspectMatchingDOMElement = true;
+      }
+      if (supportsClickToInspect) {
+        this._supportsClickToInspect = true;
       }
       if (supportsReloadAndProfile) {
         this._supportsReloadAndProfile = true;
@@ -437,8 +443,12 @@ export default class Store extends EventEmitter<{
     return this._rootSupportsTimelineProfiling;
   }
 
-  get supportsNativeInspection(): boolean {
-    return this._supportsNativeInspection;
+  get supportsInspectMatchingDOMElement(): boolean {
+    return this._supportsInspectMatchingDOMElement;
+  }
+
+  get supportsClickToInspect(): boolean {
+    return this._supportsClickToInspect;
   }
 
   get supportsNativeStyleEditor(): boolean {
diff --git a/packages/react-devtools-shared/src/devtools/views/Components/InspectedElement.js b/packages/react-devtools-shared/src/devtools/views/Components/InspectedElement.js
index 8688b132cb..1f1f538b6b 100644
--- a/packages/react-devtools-shared/src/devtools/views/Components/InspectedElement.js
+++ b/packages/react-devtools-shared/src/devtools/views/Components/InspectedElement.js
@@ -296,7 +296,7 @@ export default function InspectedElementWrapper(_: Props): React.Node {
             <ButtonIcon type="suspend" />
           </Toggle>
         )}
-        {store.supportsNativeInspection && (
+        {store.supportsInspectMatchingDOMElement && (
           <Button
             onClick={highlightElement}
             title="Inspect the matching DOM element">
diff --git a/packages/react-devtools-shared/src/devtools/views/Components/Tree.js b/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
index 7e15ba0514..ccc61f1c1d 100644
--- a/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
+++ b/packages/react-devtools-shared/src/devtools/views/Components/Tree.js
@@ -361,7 +361,7 @@ export default function Tree(props: Props): React.Node {
     <TreeFocusedContext.Provider value={treeFocused}>
       <div className={styles.Tree} ref={treeRef}>
         <div className={styles.SearchInput}>
-          {store.supportsNativeInspection && (
+          {store.supportsClickToInspect && (
             <Fragment>
               <InspectHostNodesToggle />
               <div className={styles.VRule} />
diff --git a/packages/react-dom-bindings/src/events/DOMPluginEventSystem.js b/packages/react-dom-bindings/src/events/DOMPluginEventSystem.js
index fe007b6209..5c3c9bffa1 100644
--- a/packages/react-dom-bindings/src/events/DOMPluginEventSystem.js
+++ b/packages/react-dom-bindings/src/events/DOMPluginEventSystem.js
@@ -52,6 +52,7 @@ import {
   enableLegacyFBSupport,
   enableCreateEventHandleAPI,
   enableScopeAPI,
+  enableOwnerStacks,
 } from 'shared/ReactFeatureFlags';
 import {createEventListenerWrapperWithPriority} from './ReactDOMEventListener';
 import {
@@ -70,6 +71,8 @@ import * as FormActionEventPlugin from './plugins/FormActionEventPlugin';
 
 import reportGlobalError from 'shared/reportGlobalError';
 
+import {runWithFiberInDEV} from 'react-reconciler/src/ReactCurrentFiber';
+
 type DispatchListener = {
   instance: null | Fiber,
   listener: Function,
@@ -255,7 +258,17 @@ function processDispatchQueueItemsInOrder(
       if (instance !== previousInstance && event.isPropagationStopped()) {
         return;
       }
-      executeDispatch(event, listener, currentTarget);
+      if (__DEV__ && enableOwnerStacks && instance !== null) {
+        runWithFiberInDEV(
+          instance,
+          executeDispatch,
+          event,
+          listener,
+          currentTarget,
+        );
+      } else {
+        executeDispatch(event, listener, currentTarget);
+      }
       previousInstance = instance;
     }
   } else {
@@ -264,7 +277,17 @@ function processDispatchQueueItemsInOrder(
       if (instance !== previousInstance && event.isPropagationStopped()) {
         return;
       }
-      executeDispatch(event, listener, currentTarget);
+      if (__DEV__ && enableOwnerStacks && instance !== null) {
+        runWithFiberInDEV(
+          instance,
+          executeDispatch,
+          event,
+          listener,
+          currentTarget,
+        );
+      } else {
+        executeDispatch(event, listener, currentTarget);
+      }
       previousInstance = instance;
     }
   }
diff --git a/packages/react-dom/package.json b/packages/react-dom/package.json
index 170471ad8a..481548f374 100644
--- a/packages/react-dom/package.json
+++ b/packages/react-dom/package.json
@@ -63,9 +63,9 @@
       "bun": "./server.bun.js",
       "deno": "./server.browser.js",
       "worker": "./server.browser.js",
-      "browser": "./server.browser.js",
       "node": "./server.node.js",
       "edge-light": "./server.edge.js",
+      "browser": "./server.browser.js",
       "default": "./server.node.js"
     },
     "./server.browser": {
@@ -89,9 +89,9 @@
       "workerd": "./static.edge.js",
       "deno": "./static.browser.js",
       "worker": "./static.browser.js",
-      "browser": "./static.browser.js",
       "node": "./static.node.js",
       "edge-light": "./static.edge.js",
+      "browser": "./static.browser.js",
       "default": "./static.node.js"
     },
     "./static.browser": {
diff --git a/packages/react-dom/src/ReactDOMFB.js b/packages/react-dom/src/ReactDOMFB.js
index 409aa376d5..4825c80dfb 100644
--- a/packages/react-dom/src/ReactDOMFB.js
+++ b/packages/react-dom/src/ReactDOMFB.js
@@ -43,6 +43,5 @@ export {
   render,
   unstable_batchedUpdates,
   findDOMNode,
-  unstable_renderSubtreeIntoContainer,
   unmountComponentAtNode,
 } from './client/ReactDOMRootFB';
diff --git a/packages/react-dom/src/__tests__/renderSubtreeIntoContainer-test.js b/packages/react-dom/src/__tests__/renderSubtreeIntoContainer-test.js
deleted file mode 100644
index 4f93cd3ac8..0000000000
--- a/packages/react-dom/src/__tests__/renderSubtreeIntoContainer-test.js
+++ /dev/null
@@ -1,353 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @emails react-core
- */
-
-'use strict';
-
-const React = require('react');
-const PropTypes = require('prop-types');
-const ReactDOM = require('react-dom');
-const ReactDOMClient = require('react-dom/client');
-const act = require('internal-test-utils').act;
-const renderSubtreeIntoContainer =
-  require('react-dom').unstable_renderSubtreeIntoContainer;
-
-describe('renderSubtreeIntoContainer', () => {
-  // @gate !disableLegacyContext
-  // @gate !disableLegacyMode
-  it('should pass context when rendering subtree elsewhere', () => {
-    const portal = document.createElement('div');
-
-    class Component extends React.Component {
-      static contextTypes = {
-        foo: PropTypes.string.isRequired,
-      };
-
-      render() {
-        return <div>{this.context.foo}</div>;
-      }
-    }
-
-    class Parent extends React.Component {
-      static childContextTypes = {
-        foo: PropTypes.string.isRequired,
-      };
-
-      getChildContext() {
-        return {
-          foo: 'bar',
-        };
-      }
-
-      render() {
-        return null;
-      }
-
-      componentDidMount() {
-        expect(
-          function () {
-            renderSubtreeIntoContainer(this, <Component />, portal);
-          }.bind(this),
-        ).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-
-    const container = document.createElement('div');
-    ReactDOM.render(<Parent />, container);
-    expect(portal.firstChild.innerHTML).toBe('bar');
-  });
-
-  // @gate !disableLegacyContext
-  // @gate !disableLegacyMode
-  it('should update context if it changes due to setState', async () => {
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const portal = document.createElement('div');
-
-    class Component extends React.Component {
-      static contextTypes = {
-        foo: PropTypes.string.isRequired,
-        getFoo: PropTypes.func.isRequired,
-      };
-
-      render() {
-        return <div>{this.context.foo + '-' + this.context.getFoo()}</div>;
-      }
-    }
-
-    class Parent extends React.Component {
-      static childContextTypes = {
-        foo: PropTypes.string.isRequired,
-        getFoo: PropTypes.func.isRequired,
-      };
-
-      state = {
-        bar: 'initial',
-      };
-
-      getChildContext() {
-        return {
-          foo: this.state.bar,
-          getFoo: () => this.state.bar,
-        };
-      }
-
-      render() {
-        return null;
-      }
-
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Component />, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-
-      componentDidUpdate() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Component />, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-    const root = ReactDOMClient.createRoot(container);
-    const parentRef = React.createRef();
-    await act(async () => {
-      root.render(<Parent ref={parentRef} />);
-    });
-    const instance = parentRef.current;
-
-    expect(portal.firstChild.innerHTML).toBe('initial-initial');
-    await act(async () => {
-      instance.setState({bar: 'changed'});
-    });
-    expect(portal.firstChild.innerHTML).toBe('changed-changed');
-  });
-
-  // @gate !disableLegacyContext
-  // @gate !disableLegacyMode
-  it('should update context if it changes due to re-render', async () => {
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const portal = document.createElement('div');
-
-    class Component extends React.Component {
-      static contextTypes = {
-        foo: PropTypes.string.isRequired,
-        getFoo: PropTypes.func.isRequired,
-      };
-
-      render() {
-        return <div>{this.context.foo + '-' + this.context.getFoo()}</div>;
-      }
-    }
-
-    class Parent extends React.Component {
-      static childContextTypes = {
-        foo: PropTypes.string.isRequired,
-        getFoo: PropTypes.func.isRequired,
-      };
-
-      getChildContext() {
-        return {
-          foo: this.props.bar,
-          getFoo: () => this.props.bar,
-        };
-      }
-
-      render() {
-        return null;
-      }
-
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Component />, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-
-      componentDidUpdate() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Component />, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<Parent bar="initial" />);
-    });
-    expect(portal.firstChild.innerHTML).toBe('initial-initial');
-    await act(async () => {
-      root.render(<Parent bar="changed" />);
-    });
-    expect(portal.firstChild.innerHTML).toBe('changed-changed');
-  });
-
-  // @gate !disableLegacyMode
-  it('should render portal with non-context-provider parent', async () => {
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const portal = document.createElement('div');
-
-    class Parent extends React.Component {
-      render() {
-        return null;
-      }
-
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <div>hello</div>, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<Parent bar="initial" />);
-    });
-    expect(portal.firstChild.innerHTML).toBe('hello');
-  });
-
-  // @gate !disableLegacyContext
-  // @gate !disableLegacyMode
-  it('should get context through non-context-provider parent', async () => {
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const portal = document.createElement('div');
-
-    class Parent extends React.Component {
-      render() {
-        return <Middle />;
-      }
-      getChildContext() {
-        return {value: this.props.value};
-      }
-      static childContextTypes = {
-        value: PropTypes.string.isRequired,
-      };
-    }
-
-    class Middle extends React.Component {
-      render() {
-        return null;
-      }
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Child />, portal);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-
-    class Child extends React.Component {
-      static contextTypes = {
-        value: PropTypes.string.isRequired,
-      };
-      render() {
-        return <div>{this.context.value}</div>;
-      }
-    }
-
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<Parent value="foo" />);
-    });
-    expect(portal.textContent).toBe('foo');
-  });
-
-  // @gate !disableLegacyContext
-  // @gate !disableLegacyMode
-  it('should get context through middle non-context-provider layer', async () => {
-    const container = document.createElement('div');
-    document.body.appendChild(container);
-    const portal1 = document.createElement('div');
-    const portal2 = document.createElement('div');
-
-    class Parent extends React.Component {
-      render() {
-        return null;
-      }
-      getChildContext() {
-        return {value: this.props.value};
-      }
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Middle />, portal1);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-      static childContextTypes = {
-        value: PropTypes.string.isRequired,
-      };
-    }
-
-    class Middle extends React.Component {
-      render() {
-        return null;
-      }
-      componentDidMount() {
-        expect(() => {
-          renderSubtreeIntoContainer(this, <Child />, portal2);
-        }).toErrorDev(
-          'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported since React 18',
-        );
-      }
-    }
-
-    class Child extends React.Component {
-      static contextTypes = {
-        value: PropTypes.string.isRequired,
-      };
-      render() {
-        return <div>{this.context.value}</div>;
-      }
-    }
-
-    const root = ReactDOMClient.createRoot(container);
-    await act(async () => {
-      root.render(<Parent value="foo" />);
-    });
-    expect(portal2.textContent).toBe('foo');
-  });
-
-  // @gate !disableLegacyMode
-  it('legacy test: fails gracefully when mixing React 15 and 16', () => {
-    class C extends React.Component {
-      render() {
-        return <div />;
-      }
-    }
-    const c = ReactDOM.render(<C />, document.createElement('div'));
-    // React 15 calls this:
-    // https://github.com/facebook/react/blob/77b71fc3c4/src/renderers/dom/client/ReactMount.js#L478-L479
-    expect(() => {
-      c._reactInternalInstance._processChildContext({});
-    }).toThrow(
-      __DEV__
-        ? '_processChildContext is not available in React 16+. This likely ' +
-            'means you have multiple copies of React and are attempting to nest ' +
-            'a React 15 tree inside a React 16 tree using ' +
-            "unstable_renderSubtreeIntoContainer, which isn't supported. Try to " +
-            'make sure you have only one copy of React (and ideally, switch to ' +
-            'ReactDOM.createPortal).'
-        : "Cannot read property '_processChildContext' of undefined",
-    );
-  });
-});
diff --git a/packages/react-dom/src/client/ReactDOMRootFB.js b/packages/react-dom/src/client/ReactDOMRootFB.js
index 64a1cf12ac..1e56097266 100644
--- a/packages/react-dom/src/client/ReactDOMRootFB.js
+++ b/packages/react-dom/src/client/ReactDOMRootFB.js
@@ -59,7 +59,6 @@ import {
 } from 'react-reconciler/src/ReactFiberReconciler';
 import {LegacyRoot} from 'react-reconciler/src/ReactRootTags';
 import getComponentNameFromType from 'shared/getComponentNameFromType';
-import {has as hasInstance} from 'shared/ReactInstanceMap';
 
 import {
   current as currentOwner,
@@ -420,46 +419,6 @@ export function render(
   );
 }
 
-export function unstable_renderSubtreeIntoContainer(
-  parentComponent: React$Component<any, any>,
-  element: React$Element<any>,
-  containerNode: Container,
-  callback: ?Function,
-): React$Component<any, any> | PublicInstance | null {
-  if (disableLegacyMode) {
-    if (__DEV__) {
-      console.error(
-        'ReactDOM.unstable_renderSubtreeIntoContainer() was removed in React 19. Consider using a portal instead.',
-      );
-    }
-    throw new Error('ReactDOM: Unsupported Legacy Mode API.');
-  }
-  if (__DEV__) {
-    console.error(
-      'ReactDOM.unstable_renderSubtreeIntoContainer() has not been supported ' +
-        'since React 18. Consider using a portal instead. Until you switch to ' +
-        "the createRoot API, your app will behave as if it's running React " +
-        '17. Learn more: https://react.dev/link/switch-to-createroot',
-    );
-  }
-
-  if (!isValidContainerLegacy(containerNode)) {
-    throw new Error('Target container is not a DOM element.');
-  }
-
-  if (parentComponent == null || !hasInstance(parentComponent)) {
-    throw new Error('parentComponent must be a valid React Component');
-  }
-
-  return legacyRenderSubtreeIntoContainer(
-    parentComponent,
-    element,
-    containerNode,
-    false,
-    callback,
-  );
-}
-
 export function unmountComponentAtNode(container: Container): boolean {
   if (disableLegacyMode) {
     if (__DEV__) {
diff --git a/packages/react-native-renderer/src/legacy-events/EventPluginUtils.js b/packages/react-native-renderer/src/legacy-events/EventPluginUtils.js
index f97d7b5488..02444e079a 100644
--- a/packages/react-native-renderer/src/legacy-events/EventPluginUtils.js
+++ b/packages/react-native-renderer/src/legacy-events/EventPluginUtils.js
@@ -7,6 +7,10 @@
 
 import isArray from 'shared/isArray';
 
+import {enableOwnerStacks} from 'shared/ReactFeatureFlags';
+
+import {runWithFiberInDEV} from 'react-reconciler/src/ReactCurrentFiber';
+
 let hasError = false;
 let caughtError = null;
 
@@ -93,10 +97,22 @@ export function executeDispatchesInOrder(event) {
         break;
       }
       // Listeners and Instances are two parallel arrays that are always in sync.
-      executeDispatch(event, dispatchListeners[i], dispatchInstances[i]);
+      const listener = dispatchListeners[i];
+      const instance = dispatchInstances[i];
+      if (__DEV__ && enableOwnerStacks && instance !== null) {
+        runWithFiberInDEV(instance, executeDispatch, event, listener, instance);
+      } else {
+        executeDispatch(event, listener, instance);
+      }
     }
   } else if (dispatchListeners) {
-    executeDispatch(event, dispatchListeners, dispatchInstances);
+    const listener = dispatchListeners;
+    const instance = dispatchInstances;
+    if (__DEV__ && enableOwnerStacks && instance !== null) {
+      runWithFiberInDEV(instance, executeDispatch, event, listener, instance);
+    } else {
+      executeDispatch(event, listener, instance);
+    }
   }
   event._dispatchListeners = null;
   event._dispatchInstances = null;
diff --git a/packages/react-reconciler/src/ReactFiberClassComponent.js b/packages/react-reconciler/src/ReactFiberClassComponent.js
index 6bf04da4b4..5a7692949b 100644
--- a/packages/react-reconciler/src/ReactFiberClassComponent.js
+++ b/packages/react-reconciler/src/ReactFiberClassComponent.js
@@ -73,9 +73,7 @@ import {
   setIsStrictModeForDevtools,
 } from './ReactFiberDevToolsHook';
 
-const fakeInternalInstance: {
-  _processChildContext?: () => empty,
-} = {};
+const fakeInternalInstance = {};
 
 let didWarnAboutStateAssignmentForComponent;
 let didWarnAboutUninitializedState;
@@ -98,24 +96,6 @@ if (__DEV__) {
   didWarnAboutInvalidateContextType = new Set<string>();
   didWarnOnInvalidCallback = new Set<string>();
 
-  // This is so gross but it's at least non-critical and can be removed if
-  // it causes problems. This is meant to give a nicer error message for
-  // ReactDOM15.unstable_renderSubtreeIntoContainer(reactDOM16Component,
-  // ...)) which otherwise throws a "_processChildContext is not a function"
-  // exception.
-  Object.defineProperty(fakeInternalInstance, '_processChildContext', {
-    enumerable: false,
-    value: function (): empty {
-      throw new Error(
-        '_processChildContext is not available in React 16+. This likely ' +
-          'means you have multiple copies of React and are attempting to nest ' +
-          'a React 15 tree inside a React 16 tree using ' +
-          "unstable_renderSubtreeIntoContainer, which isn't supported. Try " +
-          'to make sure you have only one copy of React (and ideally, switch ' +
-          'to ReactDOM.createPortal).',
-      );
-    },
-  });
   Object.freeze(fakeInternalInstance);
 }
 
diff --git a/packages/react-server/src/forks/ReactServerStreamConfig.dom-fb-experimental.js b/packages/react-server/src/forks/ReactServerStreamConfig.dom-fb-experimental.js
deleted file mode 100644
index 2d705e2a1c..0000000000
--- a/packages/react-server/src/forks/ReactServerStreamConfig.dom-fb-experimental.js
+++ /dev/null
@@ -1,99 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @flow
- */
-
-export * from '../ReactServerStreamConfigFB';
-
-import type {
-  PrecomputedChunk,
-  Chunk,
-  BinaryChunk,
-} from '../ReactServerStreamConfigFB';
-
-let byteLengthImpl: null | ((chunk: Chunk | PrecomputedChunk) => number) = null;
-
-export function setByteLengthOfChunkImplementation(
-  impl: (chunk: Chunk | PrecomputedChunk) => number,
-): void {
-  byteLengthImpl = impl;
-}
-
-export function byteLengthOfChunk(chunk: Chunk | PrecomputedChunk): number {
-  if (byteLengthImpl == null) {
-    // eslint-disable-next-line react-internal/prod-error-codes
-    throw new Error(
-      'byteLengthOfChunk implementation is not configured. Please, provide the implementation via ReactFlightDOMServer.setConfig(...);',
-    );
-  }
-  return byteLengthImpl(chunk);
-}
-
-export interface Destination {
-  beginWriting(): void;
-  write(chunk: Chunk | PrecomputedChunk | BinaryChunk): void;
-  completeWriting(): void;
-  flushBuffered(): void;
-  close(): void;
-  onError(error: mixed): void;
-}
-
-function handleErrorInNextTick(error: any) {
-  setTimeout(() => {
-    throw error;
-  });
-}
-
-const LocalPromise = Promise;
-
-/**
- * Since this environment doesn't have a way to schedule tasks from JS we schedule
- * using a microtask instead. This isn't necessarily ideal since we would like to give
- * other IO a chance to run before performing work typically but it's the best we can
- * do in this environment
- */
-export function scheduleWork(callback: () => void) {
-  LocalPromise.resolve().then(callback).catch(handleErrorInNextTick);
-}
-
-export const scheduleMicrotask: (callback: () => void) => void = scheduleWork;
-
-export function beginWriting(destination: Destination) {
-  destination.beginWriting();
-}
-
-export function writeChunk(
-  destination: Destination,
-  chunk: Chunk | PrecomputedChunk | BinaryChunk,
-): void {
-  destination.write(chunk);
-}
-
-export function writeChunkAndReturn(
-  destination: Destination,
-  chunk: Chunk | PrecomputedChunk | BinaryChunk,
-): boolean {
-  destination.write(chunk);
-  return true;
-}
-
-export function completeWriting(destination: Destination) {
-  destination.completeWriting();
-}
-
-export function flushBuffered(destination: Destination) {
-  destination.flushBuffered();
-}
-
-export function close(destination: Destination) {
-  destination.close();
-}
-
-export function closeWithError(destination: Destination, error: mixed): void {
-  destination.onError(error);
-  destination.close();
-}
diff --git a/packages/shared/ReactInstanceMap.js b/packages/shared/ReactInstanceMap.js
index 7eab16f55b..2ad235c7a5 100644
--- a/packages/shared/ReactInstanceMap.js
+++ b/packages/shared/ReactInstanceMap.js
@@ -15,23 +15,10 @@
  * If this becomes an actual Map, that will break.
  */
 
-/**
- * This API should be called `delete` but we'd have to make sure to always
- * transform these to strings for IE support. When this transform is fully
- * supported we can rename it.
- */
-export function remove(key) {
-  key._reactInternals = undefined;
-}
-
 export function get(key) {
   return key._reactInternals;
 }
 
-export function has(key) {
-  return key._reactInternals !== undefined;
-}
-
 export function set(key, value) {
   key._reactInternals = value;
 }
diff --git a/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js b/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
index 1ad3de60da..6f7232674a 100644
--- a/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
+++ b/packages/use-sync-external-store/src/__tests__/useSyncExternalStoreShared-test.js
@@ -20,7 +20,7 @@ let useState;
 let useEffect;
 let useLayoutEffect;
 let assertLog;
-let originalError;
+let assertConsoleErrorDev;
 
 // This tests shared behavior between the built-in and shim implementations of
 // of useSyncExternalStore.
@@ -50,9 +50,6 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
             : 'react-dom-17/umd/react-dom.production.min.js',
         ),
       );
-      // Because React 17 prints extra logs we need to ignore them.
-      originalError = console.error;
-      console.error = jest.fn();
     }
     React = require('react');
     ReactDOM = require('react-dom');
@@ -63,6 +60,7 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
     useLayoutEffect = React.useLayoutEffect;
     const InternalTestUtils = require('internal-test-utils');
     assertLog = InternalTestUtils.assertLog;
+    assertConsoleErrorDev = InternalTestUtils.assertConsoleErrorDev;
     const internalAct = require('internal-test-utils').act;
 
     // The internal act implementation doesn't batch updates by default, since
@@ -85,11 +83,6 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
     useSyncExternalStoreWithSelector =
       require('use-sync-external-store/shim/with-selector').useSyncExternalStoreWithSelector;
   });
-  afterEach(() => {
-    if (gate(flags => flags.enableUseSyncExternalStoreShim)) {
-      console.error = originalError;
-    }
-  });
   function Text({text}) {
     Scheduler.log(text);
     return text;
@@ -630,36 +623,30 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
     const container = document.createElement('div');
     const root = createRoot(container);
     await expect(async () => {
-      await expect(async () => {
-        await act(() => {
-          ReactDOM.flushSync(async () =>
-            root.render(React.createElement(App, null)),
-          );
-        });
-      }).rejects.toThrow(
-        'Maximum update depth exceeded. This can happen when a component repeatedly ' +
-          'calls setState inside componentWillUpdate or componentDidUpdate. React limits ' +
-          'the number of nested updates to prevent infinite loops.',
-      );
-    }).toErrorDev(
+      await act(() => {
+        ReactDOM.flushSync(async () =>
+          root.render(React.createElement(App, null)),
+        );
+      });
+    }).rejects.toThrow(
+      'Maximum update depth exceeded. This can happen when a component repeatedly ' +
+        'calls setState inside componentWillUpdate or componentDidUpdate. React limits ' +
+        'the number of nested updates to prevent infinite loops.',
+    );
+
+    assertConsoleErrorDev(
       gate(flags => flags.enableUseSyncExternalStoreShim)
         ? [
-            'Maximum update depth exceeded. ',
-            'The result of getSnapshot should be cached to avoid an infinite loop',
-            'The above error occurred in the',
+            [
+              'The result of getSnapshot should be cached to avoid an infinite loop',
+              {withoutStack: true},
+            ],
+            'Error: Maximum update depth exceeded',
+            'The above error occurred i',
           ]
         : [
             'The result of getSnapshot should be cached to avoid an infinite loop',
           ],
-      {
-        withoutStack: gate(flags => {
-          if (flags.enableUseSyncExternalStoreShim) {
-            // Stacks don't work when mixing the source and the npm package.
-            return flags.source ? 1 : 0;
-          }
-          return false;
-        }),
-      },
     );
   });
   it('getSnapshot can return NaN without infinite loop warning', async () => {
@@ -850,10 +837,9 @@ describe('Shared useSyncExternalStore behavior (shim and built-in)', () => {
         // client. To avoid this server mismatch warning, user must account for
         // this themselves and return the correct value inside `getSnapshot`.
         await act(() => {
-          expect(() =>
-            ReactDOM.hydrate(React.createElement(App, null), container),
-          ).toErrorDev('Text content did not match');
+          ReactDOM.hydrate(React.createElement(App, null), container);
         });
+        assertConsoleErrorDev(['Text content did not match']);
         assertLog(['client', 'Passive effect: client']);
       }
       expect(container.textContent).toEqual('client');
diff --git a/packages/use-sync-external-store/src/useSyncExternalStore.js b/packages/use-sync-external-store/src/useSyncExternalStore.js
index ba8e62499a..8d6c49105d 100644
--- a/packages/use-sync-external-store/src/useSyncExternalStore.js
+++ b/packages/use-sync-external-store/src/useSyncExternalStore.js
@@ -16,7 +16,10 @@ import * as React from 'react';
 export const useSyncExternalStore = React.useSyncExternalStore;
 
 if (__DEV__) {
-  console.error(
+  // Avoid transforming the `console.error` call as it would cause the built artifact
+  // to access React internals, which exist under different paths depending on the
+  // React version.
+  console['error'](
     "The main 'use-sync-external-store' entry point is not supported; all it " +
       "does is re-export useSyncExternalStore from the 'react' package, so " +
       'it only works with React 18+.' +
diff --git a/packages/use-sync-external-store/src/useSyncExternalStoreShimClient.js b/packages/use-sync-external-store/src/useSyncExternalStoreShimClient.js
index 2bda9f11bf..579933f3dd 100644
--- a/packages/use-sync-external-store/src/useSyncExternalStoreShimClient.js
+++ b/packages/use-sync-external-store/src/useSyncExternalStoreShimClient.js
@@ -40,7 +40,10 @@ export function useSyncExternalStore<T>(
     if (!didWarnOld18Alpha) {
       if (React.startTransition !== undefined) {
         didWarnOld18Alpha = true;
-        console.error(
+        // Avoid transforming the `console.error` call as it would cause the built artifact
+        // to access React internals, which exist under different paths depending on the
+        // React version.
+        console['error'](
           'You are using an outdated, pre-release alpha of React 18 that ' +
             'does not support useSyncExternalStore. The ' +
             'use-sync-external-store shim will not work correctly. Upgrade ' +
@@ -59,7 +62,10 @@ export function useSyncExternalStore<T>(
     if (!didWarnUncachedGetSnapshot) {
       const cachedValue = getSnapshot();
       if (!is(value, cachedValue)) {
-        console.error(
+        // Avoid transforming the `console.error` call as it would cause the built artifact
+        // to access React internals, which exist under different paths depending on the
+        // React version.
+        console['error'](
           'The result of getSnapshot should be cached to avoid an infinite loop',
         );
         didWarnUncachedGetSnapshot = true;
diff --git a/react.code-workspace b/react.code-workspace
new file mode 100644
index 0000000000..16ff05dce9
--- /dev/null
+++ b/react.code-workspace
@@ -0,0 +1,30 @@
+{
+  "folders": [
+    {
+      "path": "."
+    }
+  ],
+  "extensions": {
+    "recommendations": [
+      "dbaeumer.vscode-eslint",
+      "editorconfig.editorconfig",
+      "esbenp.prettier-vscode",
+      "flowtype.flow-for-vscode"
+    ]
+  },
+  "settings": {
+    "search.exclude": {
+      "**/dist/**": true,
+      "**/build/**": true,
+      "**/out/**": true,
+      "*.map": true,
+      "*.log": true
+    },
+    "javascript.validate.enable": false,
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "esbenp.prettier-vscode",
+    "flow.pathToFlow": "${workspaceFolder}/node_modules/.bin/flow",
+    "prettier.configPath": "",
+    "prettier.ignorePath": ""
+  }
+}
diff --git a/scripts/jest/TestFlags.js b/scripts/jest/TestFlags.js
index 0434529ab8..4e81149f2a 100644
--- a/scripts/jest/TestFlags.js
+++ b/scripts/jest/TestFlags.js
@@ -95,13 +95,8 @@ function getTestFlags() {
 
       // This is used by useSyncExternalStoresShared-test.js to decide whether
       // to test the shim or the native implementation of useSES.
-      // TODO: It's disabled when enableRefAsProp is on because the JSX
-      // runtime used by our tests is not compatible with older versions of
-      // React. If we want to keep testing this shim after enableRefIsProp is
-      // on everywhere, we'll need to find some other workaround. Maybe by
-      // only using createElement instead of JSX in that test module.
-      enableUseSyncExternalStoreShim:
-        !__VARIANT__ && !featureFlags.enableRefAsProp,
+
+      enableUseSyncExternalStoreShim: !__VARIANT__,
 
       // If there's a naming conflict between scheduler and React feature flags, the
       // React ones take precedence.