Of course any RF lens can be used with the EOS R and get great results. But don’t you think that Canon is going to release a more professional body with even better autofocus and ergonomics for large heavy lenses? To be honest it’s a rhetorical question because of course they are so I’m kinda finding it hard to see the point you are trying to make?What do you mean by "full potential"? EOS R has the best single AF in Canon history; far better than any DSLR before it. The 30MP sensor is the best sensor Canon has. Its weather sealing is as good as 5D IV. Its ergonomy is great and the body is solid.
So what is holding EOS R to be used as the camera with RF 50mm f1.2L, for example?