If he's adamant that he doesn't want to graduate early (does he mean "early" or "earlier" by the way?) then homeschooling may be literally your only option.

Putting the brakes on additional acceleration within a B&M environment, as you've discovered, may be quite difficult if that's about all they have left to offer in the way of differentiated content/instruction.

We have noted the same phenomenon, btw; DD14 was more than ready for college-level work at 10-12yo, but not for "college" at that age.


Schrödinger's cat walks into a bar. And doesn't.