I would also recommend asking the school to do achievement testing for your DS. If the school finds on its own tests how much your DS is advanced, they might be more willing to try to differentiate for him before any GATE program begins. Also, your DS seems very mature, and maybe he can help out by doing a little self-advocacy. (I only have a DS6, so I'm no help in offering up how the self-advocacy would work, but maybe others can chime in.)