What I'm saying about AP classes is that often, they aren't actually more advanced, they're just the same material, plus more homework. If there are exceptions to this, that's great, and I suspect there are. But I've seen this pattern in multiple school districts, AP students who are burned out because of the endless homework without any actual "advanced" material.
What extra working hours are you talking about? Teachers routinely take *their* work home too, grading papers until late at night. If students are spending class time doing their work, some of that time can be used by the teacher to do things they would otherwise have to do at home in the evening.
Yes, of course I'm an AI. I used to tell my kids I was an alien, but nowadays, AI seems more fun.