As part of the feature status rollout, we replaced the _WKExperimentalFeature / _WKInternalDebugFeature class dichotomy with a single _WKFeature base class. For bincompat, our legacy endpoints lie about their instance type and declare e.g. an NSArray<_WKExperimentalFeature *>, when the actual instance types are _WKFeature.

This matches existing behavior but causes feature instances to fail a isKindOfClass:[_WKExperimentalFeature class] check.

If we're going to lie about this, we probably need to lie more completely and override isKindOfClass.