Mulligan was brilliant, I agree.

As for the controversy over the prosthetics, I also think it's a storm in a teacup. It's hardly Goebbels propaganda so there's no case to answer. (I'm also Jewish by the way, by descent via my maternal grandmother.)

I think casting needs to be approached on a case by case basis, depending on the project/genre/character, and not based on silly blanket rules. We accept Ben Kingsley as Indian (Gandhi), Iranian (House of Sand and Fog), and Jewish (Schindler's List), so why not accept Cooper as Jewish in Maestro? It's called acting for a reason.