You sounds like you have a very good handle on things, but I know it’s impossible not to worry. If it helps, I think the concerns about lack of challenge leading to disastrous college experiences can really vary. I think the individual personality and approach to self-challenge, curiosity, or internal motivations are a huge factor. I do worry about my DS, who has become quite disengaged with formal education, but he is still able to garner enthusiasm for his own projects, so hopefully that will see him through.
My DD sounds similar to yours, in that she relished the opportunity to delve deep, and when she could, did her own “extensions” or enrichment even in school; it was just part of her nature. So despite little to no challenge in hs, she has been knocking it out of the park in college- you can just feel her expand into the opened-up opportunities, if that makes sense. She has been ready for years (decades, almost) and can hardly contain herself.
