Never heard that one (it may indeed be used that way, but if it were the only reason Apple would probably keep it in the Apple internal parts of their OS instal

Never heard that one (it may indeed be used that way, but if it were the only reason Apple would probably keep it in the Apple internal parts of their OS installs). It would also be of limited use, as the engine is purely CPU based; it is single threaded and does not even use SIMD AFAIK, let alone GPU features or the neural engines.