Saw him tonight for Harrisburg in Richmond.
I'd drop the grade at the top of this thread to a 40 FV at best. The 3B defense is there (solid MLB to possible plus), but I can't see him hitting major league pitching.
There's nothing especially wrong with his swing, his approach, or anything. He's just not good enough. And he's not young for level or from any weird background (he played in the SEC), so there's nothing that explains it other than he's just not a good enough hitter. He swings through far too much stuff in AA to have a chance against MLB pitching unless he gets significantly better.