Thanks for these tips! Regarding the EdX and Coursera classes - did the application distinguish between taking the classes for an official certificate ($49 I think), or just self-study (free)? My son likes the EdX classes, but usually the topics he wants are archived - so he can watch the video lectures and work on problem sets, but there isn't a teacher available and there are no due dates (and certificates are not even offered). Although it would be nice to have the certificates, it also might steer him toward choosing topics just because they offer a certificate - and not because they are the most interesting to him. Just wondering if the college app makes that distinction.

Also noticed that Caltech, MIT, and Harvey Mudd have recently dropped SAT subject test requirements for 2021 applicants and beyond. They aren't even optional - the schools won't look at them.