importance of 9/10 grades when applying?

hello! (fyi this is my first post, apologies if I miss some conventions of posts here)

For context, I am a student in 11th grade right now attending an international school-- we are following the IB diploma system.

Before highschool (9th grade) I was homeschooled, where my grades were externally checked and all of them were the highest according the grading system of my country.

I think it may be the reason why I struggled quite a bit with some grades when I moved to my current IRL international school, especially in 9th/10th grade in one specific criterion in mathematics, though I took the hardest class there-- (for frame of reference, my grades were "average" but not necessarily stellar either…)

(As a note, my school follows the MYP system until 10th grade, hence why on my transcript there are grades from 5/6-8 in different criteria for each subject)

Currently, I am taking the hardest maths class as well as physics/computer science as my Higher Level subjects and have gotten full marks on the last two (I am working on my mathematics criterion); I also have a some international hackathons, leadership positions in clubs and a lot of tinkering with software/hardware projects to my name (I've also organised hackathons for 50+ in my area). I hope to study computer science/electrical engineering in the future, at MIT if I'm not reaching high, maybe?

My question is as follows: how much do places like MIT value 9th/10th grades? What about improvement during 11th/12th grade?

Thank you so much in advance!! I've been stressed about this for so so long.