@jsmith As much as you or I may wish that test scores were not a filter (and if you have ever read any of my posts, I am not a fan of so much reliance on standardized test scores), the reality is that they are at this point in time. Schools like CalTech which require them are going to see your math scores as weak.
Apply to schools that appeal to you, but do NOT be discouraged if you end up at a lower ranked program. Attend and shine. Look, my ds scored a 750 on the math 2 in 9th grade. He graduated from high school with college credit for numerous math and physics courses. He took 400 level physics classes his freshman yr. And he attends Alabama…not a powerhouse physics university. But he has awesome professors. He has great research mentors. His research opportunities have taught him a ton outside of classroom topics. (I don’t even know how many languages he can program in…a huge benefit bc different projects use different languages.) He is thriving and creating an awesome UG experience. It is possible to accomplish your goals outside of MIT, UChicago, and CalTech. You can aim for them for grad school. (And in case you are wondering why our ds ended up at Bama, it is bc of their generous scholarships and their research honors program. He has zero regrets about where he is and he loves it there.)