My advice is stay at the school he's at, and work harder than ever. Do everything he can to get in a top level summer league, even as an occasional sub (there may be opportunities for a week or two in a high level league due to injuries or a team going to Omaha etc, especially for a Catcher)
If his goal is to play pro Baseball, he can get scouted from where he is at. His focus should be on his own development & getting in the best summer league(s) he can, not on trying to sit out a year due to transfer rules. Pro Baseball always has a need for Catchers...