Eagle Mum - does he have ADHD or ASD? I assume he was disappointed of the grade 6 booklet as it was too easy? I suppose you could've pointed out that contemplating infinite sets of rational/irrational numbers and doing regular work are not mutually exclusive. At least he could've saved a significant amount of time. But what's done is done. And if he's happy it's fine.
No, he definitely does not have ADHD or ASD. He was just extremely focused for that age in his preschool years. He has since developed in the arts of multitasking and social interactions. He was extremely successful in high school, academically, as well as in sports and music and is at college now. Last year, as a sophomore, he was his college’s head sports coach, Div A athlete, sports rep, choir pianist, band keyboard player, chess representative, talent show winner (with blindfold speedcubing) and student council member. All whilst maintaining a perfect GPA in engineering, an active social life and working as a tutor and proofreader of commercial maths resources (he’s been employed since age 14 because his focus enabled him to find mistakes that more mature proofreaders missed). We have no regrets - the path we let him choose for himself, at our local public school, allowed him freedom to self develop.
WRT to OP’s choice of school options, in this digital age, kids can access resources without the school needing to provide it. There was no robotics club at our local primary school, but DS had already taught himself programming with free Python and other programs, so the P & C committee asked him to run a robotics club during lunchtime. Unfortunately, he declined because it would have reduced the time he had to play handball, but the point is, there are options to implement new things if there is the need and desire.