Hey I’m just sitting in the cheap seats here and being an armchair QB to borrow a couple cliches. But the OP’s son is taking Calc 1, FY writing, humanities and a social science class. That’s a pretty basic or standard freshman LSA schedule from what I understand.
Even with 4 classes and labs, a student should still have plenty of down time. I could be totally wrong, but if you’re dropping down to 3 LSA classes, then to me, that’s not a good signal.
Your son is in Engineering, Computers, Engineering, Calc, Physics, Chem, etc. Those classes I think deserve a more “try it out” approach.
The OP’s son was admitted to UMich, so he’s a darn good student.