update RN to 0.70 (untested)

ios/app/AppDelegate.mm

@@ -22,6 +22,8 @@
 
 #import <react/config/ReactNativeConfig.h>
 
+static NSString *const kRNConcurrentRoot = @"concurrentRoot";
+
 @interface AppDelegate () <RCTCxxBridgeDelegate, RCTTurboModuleManagerDelegate> {
   RCTTurboModuleManager *_turboModuleManager;
   RCTSurfacePresenterBridgeAdapter *_bridgeAdapter;
@@ -47,7 +49,8 @@
   bridge.surfacePresenter = _bridgeAdapter.surfacePresenter;
 #endif
 
-  UIView *rootView = RCTAppSetupDefaultRootView(bridge, @"xyz.blueskyweb.app", nil);
+  NSDictionary *initProps = [self prepareInitialProps];
+  UIView *rootView = RCTAppSetupDefaultRootView(bridge, @"RnDiffApp", initProps);
 
   if (@available(iOS 13.0, *)) {
     rootView.backgroundColor = [UIColor systemBackgroundColor];
@@ -67,6 +70,25 @@
   return YES;
 }
 
+/// This method controls whether the `concurrentRoot`feature of React18 is turned on or off.
+///
+/// @see: https://reactjs.org/blog/2022/03/29/react-v18.html
+/// @note: This requires to be rendering on Fabric (i.e. on the New Architecture).
+/// @return: `true` if the `concurrentRoot` feture is enabled. Otherwise, it returns `false`.
+- (BOOL)concurrentRootEnabled
+{
+  // Switch this bool to turn on and off the concurrent root
+  return true;
+}
+- (NSDictionary *)prepareInitialProps
+{
+  NSMutableDictionary *initProps = [NSMutableDictionary new];
+#ifdef RCT_NEW_ARCH_ENABLED
+  initProps[kRNConcurrentRoot] = @([self concurrentRootEnabled]);
+#endif
+  return initProps;
+}
+
 - (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
 {
 #if DEBUG