I love what you say about your son's baseball experience. And it's great that he knows what he wants to study in college.
If he's a 2023 grad, applications are due in a few weeks. Has he applied to schools? does he have a list of schools where he plans to apply to study engineering? There are plenty of excellent D3 schools with engineering majors on their baseball teams. If your son can get into one without baseball coach support with admissions, then why not do that? Once he knows about admissions, contact the baseball coach.
Given his grades/SAT, if he would need the support of the baseball coach to be admitted, then he's missed the Early Decision circus, but things sometimes change, he could still contact a coach and ask about support. 6'7" pitchers don't grow on trees.
The threads purely about engineering are a few years old, there's one from 2016:
https://community.hsbaseballwe...chools-with-baseball
This post might be relevant: