[iOS] Layout Animation no effect

[wgywgy]

RN Version: 0.68.1
Problem: When I run rn-tester project, The Layout Animation Demo click 'Add View' has no animate effect.

[wgywgy]

Hello, I find Layout animation enabled is control by this code:

- (instancetype)initWithToolbox:(SchedulerToolbox)toolbox
{
  if (self = [super init]) {
    auto reactNativeConfig =
        toolbox.contextContainer->at<std::shared_ptr<const ReactNativeConfig>>("ReactNativeConfig");

    _delegateProxy = std::make_shared<SchedulerDelegateProxy>((__bridge void *)self);

    if (reactNativeConfig->getBool("react_fabric:enabled_layout_animations_ios")) {
      _layoutAnimationDelegateProxy = std::make_shared<LayoutAnimationDelegateProxy>((__bridge void *)self);
      _animationDriver = std::make_shared<LayoutAnimationDriver>(
          toolbox.runtimeExecutor, toolbox.contextContainer, _layoutAnimationDelegateProxy.get());
      if (reactNativeConfig->getBool("react_fabric:enabled_skip_invalidated_key_frames_ios")) {
        _animationDriver->enableSkipInvalidatedKeyFrames();
      }
      if (reactNativeConfig->getBool("react_fabric:enable_crash_on_missing_component_descriptor")) {
        _animationDriver->enableCrashOnMissingComponentDescriptor();
      }
      if (reactNativeConfig->getBool("react_fabric:enable_simulate_image_props_memory_access")) {
        _animationDriver->enableSimulateImagePropsMemoryAccess();
      }
      _uiRunLoopObserver =
          toolbox.mainRunLoopObserverFactory(RunLoopObserver::Activity::BeforeWaiting, _layoutAnimationDelegateProxy);
      _uiRunLoopObserver->setDelegate(_layoutAnimationDelegateProxy.get());
    }

    _scheduler = std::make_unique<Scheduler>(
        toolbox, (_animationDriver ? _animationDriver.get() : nullptr), _delegateProxy.get());
  }

  return self;
}

Why this is not enabled by default?
Can I enable it by use myself ReactNativeConfig instead of EmptyReactNativeConfig?