Smart of you to look at the UWCs - check out the New Mexico campus as well.
I think it is too early for you to have a final list of schools. I understand you are doing your best to understand which schools may consider FA for an international applicant from India, but unfortunately there is no easy way to figure this out, and it is certainly more complicated than looking at the size of a school’s endowment, or the narrative on a school’s Admissions webpage.
You have a lot of time to keep crafting and expanding your list, and keep in mind the SAO application allows you to apply to many schools with essentially one application. Consider adding even more SAO schools to your list.
There will be virtual boarding school fairs throughout the Summer and Fall. Consider attending these, and as the format permits, ask questions of the admissions representatives. Google “boarding school fairs” or some combination of these words and you’ll find them, and sign-up. You can then follow-up offline with these reps. Likewise, sign up directly for school information sessions. This will be a big time investment, but it is important to learn as much as possible about each school while demonstrating your sincere interest.