Although in hindsight, I'd rather have them absolutely destroy my sleep schedule than ending up getting in to less favorable university than I got in
Seriously? If you're going to university you'll be fine regardless of where it ranks, how can that possibly be worth destroying your teenage years? Is this just social attitudes in Korea or does it actually make any difference?
Yeah but so is having a piece of paper that's slightly better than someone else's. Don't burn yourself out for either.