Hi MOTF,
I know I'm chiming in late, but I've been away from the computer for a while. I just wanted to compliment your son on his scores - they are great!
My son also took the October ACT as a 12yo. He & your ds actually got exactly the same score breakdown for English! He also did well (although not quite as well as your ds

) but bombed on the Arts & Literature section of the Reading test, which brought his Reading score down to 19 & his composite down to 24. I dunno - maybe he was just getting tired by that stage.
The Transition School sounds fantastic! I wish we had something (anything!) like that in our country. That might be motivation enough for my ds to want to take the test again as a 13yo & try & push his score up a little.
As for the IQ test, I would have thought that at 13, ceiling issues are going to come into play on any current test for a HG kid.
Anyway, qdos to your ds, & best of luck.

Cassandra