Yeah if it can be solved then that's great news. But having tried "everything" I think it would be a tough sell to switch at this point.

The momentum is clearly behind git, and has been for quite some time. None of the more recent contenders have ever become popular (bzr, fossil), though of course they have their advocates.

Having the code be reworked in-private, for a long time, too doesn't make it seem like it is ready to become usable in the short-term.