diff --git a/.github/actions/setup-xcode/action.yml b/.github/actions/setup-xcode/action.yml
index 801c4750085ad3..544b8130763aff 100644
--- a/.github/actions/setup-xcode/action.yml
+++ b/.github/actions/setup-xcode/action.yml
@@ -4,7 +4,7 @@ inputs:
   xcode-version:
     description: 'The xcode version to use'
     required: false
-    default: '16.2.0'
+    default: '16.4.0'
   platform:
     description: 'The platform to use. Valid values are: ios, ios-simulator, macos, mac-catalyst, tvos, tvos-simulator, xros, xros-simulator'
     required: false
@@ -16,21 +16,3 @@ runs:
       uses: maxim-lobanov/setup-xcode@60606e260d2fc5762a71e64e74b2174e8ea3c8bd
       with:
         xcode-version: ${{ inputs.xcode-version }}
-    - name: Setup Platform ${{ inputs.platform }}
-      if: ${{ inputs.platform != 'macos' && inputs.platform != 'mac-catalyst' }}
-      shell: bash
-      run: |
-        # https://github.com/actions/runner-images/issues/12541
-        sudo xcodebuild -runFirstLaunch
-        sudo xcrun simctl list
-
-        # Install platform based on the platform
-        if [[ "${{ inputs.platform }}" == "xros" || "${{ inputs.platform }}" == "xros-simulator" ]]; then
-          sudo xcodebuild -downloadPlatform visionOS
-        elif [[ "${{ inputs.platform }}" == "tvos" || "${{ inputs.platform }}" == "tvos-simulator" ]]; then
-          sudo xcodebuild -downloadPlatform tvOS
-        else
-          sudo xcodebuild -downloadPlatform iOS
-        fi
-
-        sudo xcodebuild -runFirstLaunch
diff --git a/.github/actions/test-ios-rntester/action.yml b/.github/actions/test-ios-rntester/action.yml
index ae665e47711649..5201b810de5c1d 100644
--- a/.github/actions/test-ios-rntester/action.yml
+++ b/.github/actions/test-ios-rntester/action.yml
@@ -6,7 +6,7 @@ inputs:
     default: 2.6.10
   run-unit-tests:
     description: whether unit tests should run or not.
-    default: "true"
+    default: false
   flavor:
     description: The flavor of the build. Must be one of "Debug", "Release".
     default: Debug
diff --git a/.github/workflows/prebuild-ios-core.yml b/.github/workflows/prebuild-ios-core.yml
index b3fa449e442c35..1eeccfeaf501ee 100644
--- a/.github/workflows/prebuild-ios-core.yml
+++ b/.github/workflows/prebuild-ios-core.yml
@@ -146,8 +146,6 @@ jobs:
       - name: Setup xcode
         if: steps.restore-ios-xcframework.outputs.cache-hit != 'true'
         uses: ./.github/actions/setup-xcode
-        with:
-          xcode-version: '16.2.0'
       - name: Yarn Install
         if: steps.restore-ios-xcframework.outputs.cache-hit != 'true'
         uses: ./.github/actions/yarn-install
diff --git a/.github/workflows/prebuild-ios-dependencies.yml b/.github/workflows/prebuild-ios-dependencies.yml
index 275b3b8bec538e..3152cb98be489d 100644
--- a/.github/workflows/prebuild-ios-dependencies.yml
+++ b/.github/workflows/prebuild-ios-dependencies.yml
@@ -124,8 +124,6 @@ jobs:
         uses: ./.github/actions/setup-node
       - name: Setup xcode
         uses: ./.github/actions/setup-xcode
-        with:
-          xcode-version: '16.1'
       - name: Restore XCFramework
         id: restore-xcframework
         uses: actions/cache/restore@v5
diff --git a/.github/workflows/test-all.yml b/.github/workflows/test-all.yml
index 1b6a19c6a09366..b5486724fbd1d1 100644
--- a/.github/workflows/test-all.yml
+++ b/.github/workflows/test-all.yml
@@ -195,7 +195,7 @@ jobs:
 
           export RCT_USE_LOCAL_RN_DEP=/tmp/third-party/ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz
           # Disable prebuilds for now, as they are causing issues with E2E tests for 0.82-stable branch
-          # export RCT_TESTONLY_RNCORE_TARBALL_PATH="/tmp/ReactCore/ReactCore${{ matrix.flavor }}.xcframework.tar.gz"
+          export RCT_TESTONLY_RNCORE_TARBALL_PATH="/tmp/ReactCore/ReactCore${{ matrix.flavor }}.xcframework.tar.gz"
           RCT_NEW_ARCH_ENABLED=$NEW_ARCH_ENABLED bundle exec pod install
 
           xcodebuild \
diff --git a/.github/workflows/test-hermes-v1-ios.yml b/.github/workflows/test-hermes-v1-ios.yml
index 44437ebb36a246..bdafd9181b815b 100644
--- a/.github/workflows/test-hermes-v1-ios.yml
+++ b/.github/workflows/test-hermes-v1-ios.yml
@@ -40,8 +40,6 @@ jobs:
 
       - name: Setup xcode
         uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: 16.4.0
 
       - name: Build iOS with retry
         uses: nick-fields/retry@v3
diff --git a/packages/rn-tester/Podfile.lock b/packages/rn-tester/Podfile.lock
index e68533f97e9ec7..86e36127619a4b 100644
--- a/packages/rn-tester/Podfile.lock
+++ b/packages/rn-tester/Podfile.lock
@@ -1,8 +1,8 @@
 PODS:
   - FBLazyVector (0.84.0-rc.0)
-  - hermes-engine (0.15.0):
-    - hermes-engine/Pre-built (= 0.15.0)
-  - hermes-engine/Pre-built (0.15.0)
+  - hermes-engine (250829098.0.5):
+    - hermes-engine/Pre-built (= 250829098.0.5)
+  - hermes-engine/Pre-built (250829098.0.5)
   - MyNativeView (0.84.0-rc.0):
     - hermes-engine
     - RCTRequired
@@ -1991,7 +1991,7 @@ EXTERNAL SOURCES:
     :path: "../react-native/Libraries/FBLazyVector"
   hermes-engine:
     :podspec: "../react-native/sdks/hermes-engine/hermes-engine.podspec"
-    :tag: hermes-v0.15.0
+    :tag: hermes-v250829098.0.5
   MyNativeView:
     :path: NativeComponentExample
   NativeCxxModuleExample:
@@ -2149,7 +2149,7 @@ EXTERNAL SOURCES:
 
 SPEC CHECKSUMS:
   FBLazyVector: 60db88825afeddb4b8fac96e70230c12bde0fa8e
-  hermes-engine: 938a9cdde5b6f097720af751658786c90769fa30
+  hermes-engine: 733c2f53c483de462d6f97993795369152db68d6
   MyNativeView: 06ffd5f7a4c400b471e230dab9920df2ba67bdd1
   NativeCxxModuleExample: 8af5455cac2bdf72402da5ed6a1b445b443b1ebc
   OCMock: 589f2c84dacb1f5aaf6e4cec1f292551fe748e74
@@ -2161,7 +2161,7 @@ SPEC CHECKSUMS:
   React: a5f1b853a4eda5dbea8d01430e322650d7cddfe5
   React-callinvoker: 50627079f30a508a8b5e4cefb71329942e60ebcf
   React-Core: 27574a6d01e033fc2fbde60c0fe8ef4a6ccec121
-  React-Core-prebuilt: a4d0e4ba023bf11c14ae79fd57d555ddc9c4e43c
+  React-Core-prebuilt: e7fa6227c9298a24b98f641c08b829d484c1bd3b
   React-CoreModules: 26bdba7a4016457ba13a6233565e8e2c55cf7368
   React-cxxreact: 2271ef9b8f53fb159949edaeb0a539d880f1fbde
   React-debug: 003f262a91683df3033fcb0f660b9f071284346f
@@ -2207,7 +2207,7 @@ SPEC CHECKSUMS:
   React-RCTPushNotification: e03bfdae0cdbda626bdb0ab326c6290b5203195c
   React-RCTRuntime: 774642b42ca8533dea31972e761af95053c378b3
   React-RCTSettings: 36efade455b8edbad99b177051be4b40c544981a
-  React-RCTTest: 0a978c0ce5be24c5c484ed88d5d92a3b73e0a1b3
+  React-RCTTest: 9b1f90df8cae57012145702f0463edd470a1fb29
   React-RCTText: d920aa8f6d55a60d590ae854368a90ff5451f215
   React-RCTVibration: f31a70e15106ed7da934d0c5b4435b0fd872a2d7
   React-rendererconsistency: 8935199fadbd672c9b6bb6e26ab14895e05a1bf7
@@ -2225,7 +2225,7 @@ SPEC CHECKSUMS:
   ReactCodegen: 59fd9793bdb850ddde0063c5d0ab6ea6efa755f5
   ReactCommon: c206b8a681ce20c4652e777a890599ceb3535797
   ReactCommon-Samples: 0f45aab5d3cca4afbf3bb799a552c797a7526200
-  ReactNativeDependencies: 76c872a08280a05a5e4434172e891a0ed69342e8
+  ReactNativeDependencies: eed00171d9e126191ccf91dd4dbed525792a4c8d
   ScreenshotManager: 58a57c417506cc5a2a16b767fd7d3b480f9673e7
   Yoga: e80453f68a32823bc6074a069aa7318875f00dc1
 
diff --git a/packages/rn-tester/RCTTest/React-RCTTest.podspec b/packages/rn-tester/RCTTest/React-RCTTest.podspec
index e96768635781f4..aaff1ebf16a29c 100644
--- a/packages/rn-tester/RCTTest/React-RCTTest.podspec
+++ b/packages/rn-tester/RCTTest/React-RCTTest.podspec
@@ -26,7 +26,7 @@ Pod::Spec.new do |s|
   s.platforms              = min_supported_versions
   s.compiler_flags         = '-Wno-nullability-completeness'
   s.source                 = source
-  s.source_files           = podspec_sources("**/*.{h,m,mm}", "**/*.h")
+  s.source_files           = "**/*.{h,m,mm}"
   s.preserve_paths         = "package.json", "LICENSE", "LICENSE-docs"
   s.framework              = "XCTest"
   s.header_dir             = "RCTTest"
diff --git a/packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj b/packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj
index 898cd14e1ca524..b165630cab1049 100644
--- a/packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj
+++ b/packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj
@@ -500,14 +500,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-frameworks-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Embed Pods Frameworks";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-frameworks-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-frameworks.sh\"\n";
@@ -543,14 +539,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-resources-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Copy Pods Resources";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-resources-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-resources.sh\"\n";
@@ -564,14 +556,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-resources-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Copy Pods Resources";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-resources-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-resources.sh\"\n";
@@ -619,14 +607,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-frameworks-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Embed Pods Frameworks";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-frameworks-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTesterIntegrationTests/Pods-RNTesterIntegrationTests-frameworks.sh\"\n";
@@ -662,14 +646,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-resources-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Copy Pods Resources";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-resources-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTester/Pods-RNTester-resources.sh\"\n";
@@ -705,14 +685,10 @@
 			inputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-frameworks-${CONFIGURATION}-input-files.xcfilelist",
 			);
-			inputPaths = (
-			);
 			name = "[CP] Embed Pods Frameworks";
 			outputFileListPaths = (
 				"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-frameworks-${CONFIGURATION}-output-files.xcfilelist",
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests-frameworks.sh\"\n";
@@ -943,7 +919,10 @@
 				IPHONEOS_DEPLOYMENT_TARGET = 15.1;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
-				OTHER_CFLAGS = "$(inherited)";
+				OTHER_CFLAGS = (
+					"$(inherited)",
+					"-DRCT_REMOVE_LEGACY_ARCH=1",
+				);
 				OTHER_CPLUSPLUSFLAGS = (
 					"$(OTHER_CFLAGS)",
 					"-DFOLLY_NO_CONFIG",
@@ -951,6 +930,7 @@
 					"-DFOLLY_USE_LIBCPP=1",
 					"-DFOLLY_CFG_NO_COROUTINES=1",
 					"-DFOLLY_HAVE_CLOCK_GETTIME=1",
+					"-DRCT_REMOVE_LEGACY_ARCH=1",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@@ -959,6 +939,7 @@
 				REACT_NATIVE_PATH = "${PODS_ROOT}/../../react-native";
 				SDKROOT = iphoneos;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = "$(inherited) DEBUG";
+				SWIFT_ENABLE_EXPLICIT_MODULES = NO;
 				USE_HERMES = true;
 				WARNING_CFLAGS = (
 					"-Wextra",
@@ -1036,7 +1017,10 @@
 				);
 				IPHONEOS_DEPLOYMENT_TARGET = 15.1;
 				MTL_ENABLE_DEBUG_INFO = NO;
-				OTHER_CFLAGS = "$(inherited)";
+				OTHER_CFLAGS = (
+					"$(inherited)",
+					"-DRCT_REMOVE_LEGACY_ARCH=1",
+				);
 				OTHER_CPLUSPLUSFLAGS = (
 					"$(OTHER_CFLAGS)",
 					"-DFOLLY_NO_CONFIG",
@@ -1044,6 +1028,7 @@
 					"-DFOLLY_USE_LIBCPP=1",
 					"-DFOLLY_CFG_NO_COROUTINES=1",
 					"-DFOLLY_HAVE_CLOCK_GETTIME=1",
+					"-DRCT_REMOVE_LEGACY_ARCH=1",
 				);
 				OTHER_LDFLAGS = (
 					"-ObjC",
@@ -1051,6 +1036,7 @@
 				);
 				REACT_NATIVE_PATH = "${PODS_ROOT}/../../react-native";
 				SDKROOT = iphoneos;
+				SWIFT_ENABLE_EXPLICIT_MODULES = NO;
 				USE_HERMES = true;
 				VALIDATE_PRODUCT = YES;
 				WARNING_CFLAGS = (