e.g. what happens when Apple says 'xyz feature isn't allowed'? Does the PWA feature set get reduced to what Apple allows? Or does the PWA have its own extra features that the native app doesn't, effectively creating two different versions of your product? 

 It's the same code base. But with minor flags for iOS vs PWA.  

 So if Apple says 'XYZ' feature isn't allowed, that means you remove that feature from the codebase? So PWA users suffer so that the codebase remains Apple kosher? 

 No.