Pretty much this. Teach them as much as they want to know. We were extremely fortunate and decided to home school our kids through elementary and middle school because a) they were learning faster than their peers and bored, and b) we had a lot of community involvement which was much better social interactions than school provided. If you are in the Bay Area and can send your kids to Reikes Nature studies[1] it is a wonderful program (as an example). Conveniently California provided all of the knowledge they "expected" kids to know[2]. Each of my children reached math proficiency differently, all of them went through calculus "C" in terms of subject matter but I don't thing the English/Business major took it past that, the other two (Physics, Bio) did.

[1] https://www.riekes.org/riekesnature

[2] https://www.cde.ca.gov/be/st/ss/ (side note, all of our kids could pass the high school "exit" exam when they started high school. I attribute this not necessarily to personal talents so much as a very low student/teacher ratio meant everyone learned things and a lack of "deadlines" on when they had to be done meant different approaches could be taken on a subject if one didn't seem to be working out)