[JJ_SO]

I think, keeping the flange distance would be a wise decision. A FF mirrorless is neither light nor small, right from the start they would have the full range of excellent lenses and later they could do simpler or better designs for wide angles.

 

Sigma did the same with theri sd quattro series and it felt pretty good. I just think, the should have placed the tripod socket more towards the mount - Sigma has some really heavy lenses - or, even better and much more elegant, put an Arca type swallow tail under their lesn tube.