I can’t comment too much on the technical feasability of using Unreal in MacOS, as using MacOS itself is extremely distasteful to me (to put it mildly 
) but when running Windows on MacOS, on my Mac Pro 7,1 (Intel), the current Radeon driver available for Bootcamp (at least on the 580X, but I’d guess quite likely on the others as well) is not compatible with Unreal. Unreal at the very least throws a warning message that you need to update your driver, and then if you bypass that warning, it runs super slow.
I can’t realistically comment on any other situation, as I’ve never been a Mac user.