I happened to be looking though DS9s records from when he had a speech delay and when he was assessed at 3 years of age he was advanced anything from 6 months to a couple of years in everything except fine motor skills- those he was age appropriate.
So I guess he was advanced at a young age, but because he had a speech delay I didn't see any of it beyond the puzzles. He was definitely pretty good at puzzles. And honestly I just assumed he if he was advanced it was because they'd been working with him.
Still think there's 2e going on, just don't know what it is. There is a note that he had a visual sequencing problem...but he's a good reader so..
