I have two boys. Same dilemma as yours. Older one went the high school route. Totally flatlined. Younger one is a sophomore and has played full season club. Can’t even compare the two. Development way better at full season. Real development takes place at 14, 15 and 16. Let the kids play where he wants just keep in mind that if he plays high school his game will get worse not better. daddy coach in the fall and a high school science teacher in the winter will not make your kid better. The quality of high school hockey is so bad that the habits kids create playing it will ruin their game
If the end-goal is realistic and aimed toward playing in college then you move on to F.S.; if the kid get playing time (again, usually as a forward) as a freshmen / sophomore then two years high school and then off to prep for a repeat year or then off to a real f.s. team. Staying in high school hockey does less than zero for the kid's game and there are tons of examples of the 'all-region' 14 year old players flaming-out before their senior year of h.s. hockey. Bad hockey, bad habits, bad coaching only pushes the kid's game one direction and that is down.