Otters - I would say the 3rd private school is worth it, especially with smaller classes and automatically accelerating by 1 grade. This is especially if you have financial issues. An automatic grade skip, yes!
Just be prepared for any transitions, gaps, and perhaps scaffold part of his executive function. Nowadays we have pomofocus.io and many time management apps, which should help your kid significantly.
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.
