Stealth,
I have a few issues with that theory from personal experience.
1. Many schools will not allow students to do that, i.e. even with Jump start (1/2 day hs 1/2 day at community college) at both of our last hs's you need permission to take more credits than is traditional, and only allowed 9 credits at te community college.
2. Except for when we were at Ft. Bragg, the neighboring hs's in other districts were at least a 30 minute drive each way. Plus, none of the schools offer summer programs that you could take to get ahead like Foreign Language or AP anything.
3. Many kids work during summer, which would make it impossible to go to school and work. DS was a lifeguard since he was 16, during the summer he worked 40 hrs a week and his hours/days rotated, he would not be able to work and go to school.
Finally, for me, personally, I also have a problem with how some of these kids feel to be competitive they must do things like that. Their resumes are out the door amazing with classes, sports, volunteerism, and working. When we went to college 20 +yrs ago, nobody I knew had 9 AP's, 300 hrs of volunteering, 3 or 4 sports, class leadership positions and worked too. The kid in our hs that got accepted MIT, had regular Physics, because we did not have AP Physics,. That is true, because he sat next to me in PSSC Physics and he was not valedictorian or salutorian, he wasn't even class president or president of NHS.. The guy who got accepted to USMA, played 1 sport (football) and did not take AP Calc, which I know for a fact because we only had 1 AP Calc class and I was in it, he wasn't. We are burning these kids out at a very young age by the stress we put on them to push themselves harder at a younger age. They are no longer kids being kids, all they are are kids busting their hump to get into their choice college, where they start taking SAT prep classes in 8th grade.
What I would say is in our current hs in NoVa it is a requirement to take gym all 4 yrs, but you theortically could take all AP's if you were deemd TAG all the way back when you were in elementary school, because by 8th grade you were taking hs level courses. DS started foreign language is 7th grade, by 8th he was in geometry. Also in our current school you can take AP/IB or ICSCE science if you test out of honors or have GC support. DD took all of the AP Eng/Lit/Psych/USH/Govt. she is weak in Math/Science so she took only Honors, but if she was strong, she would be graduating with every AP they offer, never have to take summer school and still have PE.
My personal opinion and now you can throw it in the circular filing cabinet.