you can choose one of the three, and if you choose option 3, the room will become a voice video only room (this is how I understand it). So m.ring existing isn

you can choose one of the three, and if you choose option 3, the room will become a voice video only room (this is how I understand it). So m.ring existing isn't a problem. How it is exposed in the UI, is a completely different thing, although I don't think it would be impossible to make a button that creates a room with a m.room call aka voice/video room