Although this is an interesting method that your high school has, my concern is that colleges generally also look at the senior year schedule. Most highly selective colleges emphasize the rigor of an applicant’s transcript, and although you’ve taken extremely rigorous classes in 9th-11th grade, I suspect there may be schools that have concerns about students essentially only taking three “fun” classes their senior year.
Hopefully this means that there is strong college counseling at your high school. Talk to the counselors about what college results have looked like the last couple of years for students like you.