Why does he only have a 504 rather than an IEP? If he has high I.Q.but can not perform well in school on his own, that is ground for a learning disability label which, along with his other issues, should qualify him for nan IEP. A true learning disability is a child with a high I.Q. but low performance. Unfortunately the L.D. label is used for a “catch all” for “slow learners.” A 504 is very minimal intervention/support. I can’t help but think to start by getting an IEP because it is a starting place for more support.
I do not have any answers but I am sorry for your family. I hope that you all can find the support you need.