Have you looked into the Russian School of Math. Google it, they are based out of Newton MA. They have in person classes in many states but also offer online, which we use since we are in GA where no brick and mortar exists. I have 3 kids doing it and I use it as the primary method for my kids to learn math. The public and private school instruction has been a disappointment and doesn't go into depth and teach the thinking/theoretical nature of the problems. School is about memorization and this type of program goes way beyond that. If I could drop every day math at the school I would but they don't allow it. If I was homeschooling I would use RSM only for math. My kids spend very little time like bobble heads cruising through school homework and don't need to study for school exams. They are confident and sitting at the top of their peer class loving it. Because my kids have been doing this for years when it comes to math in school they have just coasted and show up because it is just so easy. They also continue to grade accelerate them in math at school but RSM seems to stay in front of the school content leaving them confident when it comes to math in school. RSM works one year ahead relatively speaking. All my kids are on track or have hit PreCalc or Calc AB by Freshman year in high school.
The RSM program is 2-2.5 hours a week of synchronous learning and 1-1.5 hours of homework. It is 36 weeks per year and they also offer summer school programs. This program is an investment in their math foundation and future and runs at a whopping $2K a year so it is not cheap. The results are proven and you will see it quickly. They have thousands of students globally and hundreds of sections even for the online courses. As a data point of results they tout the SAT math scores for their 8th graders in San Fran of 723 of 800 vs 524... just one cohort.
We have no experience with AoPS so I can't compare but everyone who has started RSM has never left. Good luck.
https://www.russianschool.com/
