CC by blitzing is what i would try. QB has way too much time to just stand back there and throw.

I’d blitz from the ends and maybe one guy up the middle. I’d play press man coverage and bump
The receivers at the to knock the timing off.

It may be unorthodox but I’d take a fast guy and put him on the edge in the d end spot outside the tackle and just have him race in there every time switch up which side he comes from.

Gotta find a way to get pressure on the QB because most high school Defenses do not have enough fast guys to cover all the receivers in CCs but passing game and if you drop extra DBs then they just run the ball.

So, I think the best chance is to play press man and get creative to get pressure on the QB.

Unfortunately in High School most teams are not willing to change up what they normally run so until someone is willing to go all in on something to stop or atkeast slow their QB expect more of the same.