For having such a high IQ and huge memory...
I always dread sentences that begin that way.
To the basic question, we face a very similar thing with DS8. He was a early whole word reader, but he seems to have a problem dissecting words in his head into letter pieces as well as forming consistent letters in a given space on lines and judging space needed. We've held off to see if having had his amblyopia (vision issue) corrected plus time would have it self-correct. But no luck and it is slowly becoming a barrier.
The best lead we have is for an occupational therapist test for issues related to handwriting. Hopefully we can get a pediatrician referral to leverage insurance.
Despite other flexibilities at school, this is definitely one "palm to the head" thing as I'd think an occupational therapist should be available for writing+spelling challenges despite giftedness. If he pronounced F as S, he probably would get in school therapy every week.
