I never spoke with my sons' HS coach who I didn't care for. My thought was unless he's doing something that may injure them, I'm not getting involved.
In my 2022's senior year the coach left my son in for too many pitches in an early season start in what ended up being a blowout win. It was more pitches than is allowed in our conference and against the rules.
I was not happy but my son said he'd take care of it. A few days later at practice he spoke with the coach about limiting his pitch counts. The couch as was known to do, launched into an angry tirade and said something along the lines of "If you don't want to pitch for us, you don't have to....".
To say I was pissed would be an understatement...After taking time to cool off, I emailed the athletic director and pointed out that 1) A player should be able to voice concerns to the coach regarding his health and 2) This was a result of him throwing too many pitches in the previous game.
The AD responded in a politic type way CC'ing the HC which is what I expected and I would have left it at that but the HC insisted he did not pitch him more than conference rules allowed.
Our team kept a traditional scorebook and also used it for pitch counts. This was kept by a player not playing. I knew the coach of the opposing team who used iscore. I asked him what his count was and it was of course over the legal limits (more so than we initially thought). My son pitched a CG so it couldn't have been a result of not entering a pitching change. It was pretty much impossible to be off without it messing up pace of the game in iscore.
I responded back with screenshots and more detail. Crickets...But at the rest of the games that season there were multiple kids doing the book and pitch counts. I could have gone further, I have a good friend that knew the commissioner of the conference, but IMO that wouldn't have been fair to the rest of the team if any actions were taken. All I cared about was the health of my son, and maybe me bringing this up would prevent it from happening to anyone else.
TL;DR If you are concerned about your kid's health and well being speak up, but teach your kid to do it first.