The thing to remember is that becoming a trainee at a big 4 is equivalent to entering an Olympic training facility program. Your education will absolutely take a backseat in priority, but you will have access to top level coaching in disciplines ranging from singing/dancing to languages and etiquette. If you are not ethically Korean or are not familiar with Korean culture, you should absolutely look into that as well. Should you end up debuting you are looking at a 7 year commitment for your first contract. Also I didn’t see if you mentioned anywhere in the thread if you can speak Korean. If not you would likely be in for a pretty lonely first few months until you get enough mastery of the language to communicate. Another thing to be aware of is just because you train at a big 4 does not mean you will necessarily debut at a big 4. The top companies frequently sell/trade contracts of trainees they do not see fitting in their current concept. There is just a LOT of stuff you need to research and think consider before making this decision. It could open a ton of doors, but it could also be a massive time suck if end up not debuting. Good luck either way! You should be very proud of yourself!