My U13 son would like to play JV but cannot because of schedule conflicts with Club ball. I can't see him playing school ball until 9th grade and U15.

I simply can't see choosing school over Club. I'm sure there are plenty of situations where you might. But if your kid is on a Gold team at Bridge or a Premier team at CESA or an Elite team at CUFC.....there is no way you do school over Club.