I have ADHD (except I am old and they called it hyperactivity back then) and I found homework on subjects that I had already gotten to be infuriating, and tended to just skip it. I definitely lost GPA to it but because I tested so well I still ended up with a decent GPA; I also got a pass on a lot of my boredom skipping because girls weren't expected to have ADHD, the aforementioned tests, and accelerated classes (which usually moderately helped with the boredom levels, though I was always doing something simultaneous with the lecture to keep my hands busy so my brain could focus on the lecture.) I probably would have loved homeschooling, although my mother was neither patient enough to do it properly, nor had the time. In a different family situation, it likely would have been the cure for school boredom, though. But being able to just finish stuff I had and skip ahead to the next thing would have been golden.