Um, like intparent said, You should focus on improving test scores.correct me if I’m wrong. I think MIT and Harvey Mudd look more at extracurriculars and other awards you’ve won, more than simply test scores (hence Caltech having the highest average SAT score, 2310). So if you really want to have a better chance at Caltech, I would really work on getting that fresh 1600 on the sat. Otherwise, I’m not sure of what you could work on.
If you’re talking about ap tests, only the ones from Junior year and before count to colleges when they’re admitting you. (Because those are the only ones you have scores for).
Again I don’t really know what average number of AP test is for everyone because I may be an AP- holic.
But if you’re planning to do environmental engineering, wouldn’t it hurt you if you didn’t take Apes test? The bottom line is doing research at a professional level indicates that you’ve transcended regular course material so I guess you’ll be fine