I really love this idea! I was never a fan of him moving from 2B to 3B. He should have been forced to work harder at improving his weaknesses at 2B, instead of moving him to 3B and accepting his failures at 2B. We traded one of the best pitchers in baseball in 2016 for Moncada who was the #1 2B prospect.
The only reason he cant play 2B right now is he is too big and slow. He needs to lose some weight and work on increasing his flexibility and quickness which he has never worked on improving. There is no reason Moncada can't play 2B if he loses some weight, and works at it hard in the offseason to master 2B.
Btw, your comment about whether or not he will be able to handle hard coaching. The fact is, if he can't handle a hard coaching approach, then even more reason to move on and trade him. I pray we get a manager next year who is going to have tough love, demand hard work and effort and make them work on their fundamentals and defense. This what the Sox were missing the last several years and so desperately need in a manager going forward.