I just wanted to update everyone on this!
We emailed the three schools he applied to that use the CSS. They all said to wait until we found out if he was admitted.
He was admitted to WPI Early Action, they processed the appeal within about 10 days, and gave him an additional $4000 per year.
He was waitlisted at Northeastern so didn’t pursue that.
He was admitted (January start) to BU (RD), they processed the appeal in about 10 days also, and gave him an additional $6000 per year.
For the appeal we sent a letter explaining our “extraordinary“ (current) costs that are not strictly medical but are due to our children’s disabilities; documentation that half our our current savings is destined for a special needs trust for their long term care that we are in the process of establishing; and documentation of the reduced equity in our house from the bathroom renovation. Probably only the reduced equity was considered, but possibly the other info helped them know if wasn’t a “for fun” renovation.
Thank you all for your help & advice!