My 2017 was called up to varsity mid-season last year to provide a couple of starts due to games being clustered due to bad weather in the northeast. The coach (an "old-school" guy who has since departed) use our #1 starter so much, that he ended up with Tommy John during the summer. Our new coach is younger, and pitched in college during the time when pitch counts started to set in, so I am thankful for that.
My son also played for a guy who pitched recently as high as AAA, and he shows the boys things like running right after the game to get the blood pumping (and I am a fan of having him take Alleve after he pitches to decrease the swelling.
I am not so worried about pitch counts as I am good mechanics, him taking care of his body (like running after/during game when he has pitched), and giving him meds proactively to reduce swelling. Knock on wood, it has worked, and he is hopefully in line to start for the varsity squad.
The last thing I was say is that up in the northeast, we have the benefit of shorter seasons. I hear too many stories of Tommy John surgeries in other parts of the country. Not much of that up here, at least in my circle.