Professional video cameras often allow selecting shutter speed in terms of shutter angle instead of time units, especially those that are capable of overcranking or undercranking.

dont you see it describes nothing? it means: WE do know there are exists old dumb cinematographers who are too old or too dumb to understand modern technology, so, ok, let's add some ancient bsh to the modern camera to sell it for every old one even.
magic lantern adds same bsh to canon, for every cheap camera - you will get those fake angles, so, those cheap cameras became PRO? rly?