Just out of curiosity, why are you looking for a new version of the 85L? What needs improving? It is a lens I have been contemplating, and it sounds like most are very pleased with it. Looking at shots taken with it... it seems to be a lens that produces real interesting results.
The 50 1.2 L I understand it is not the sharpest... which could be improved (but some users would disagree with that and think it is part of the look it produces). But other than slow focus on the 85L, I have not read much bad about it.
Just wondering what your thoughts are on it.
Beautiful shot above, by the way. You do an excellent job and can get a lot out of what you have (probably more than your typical competition). There is no real compelling reason for you to upgrade given your current results. However, maybe a FF may allow you to push your creativity a little further than the crop body. I think that would be the business decision here, and the FF may help give a slight edge to separate you from the competition and compete at a higher level.
Good luck
Pat