I've heard nice things as well but that doesn't mean he's ready to step behind the plate and call games in the majors in 2020. Did he call his own games in college?
As far as Baumann and Kremer there is no reason to, and that is the more important part. I wish them the best of course but they are a couple of guys. Odds are good at some point their performance (or roster restraints) will dictate they get sent down. I know you love the idea of breaking the rules and messing with service time but these are two guys that have never sniffed a top 100 prospect list. They will be lucky to have four year careers in ML baseball.
Are you going to advocate sending Martin down for a month to get that extra year of former Rule V goodness?