It’s hard for me to imagine academically focused high schools that are more LGBT-friendly than the majority of the prep schools discussed on these boards, and I say that as a California parent of an LGBT prep school grad. My kiddo’s school had an all-gender dorm, a center for gender studies, policies about pronoun usage, strong faculty advocates, and a strong culture of acceptance from students and teachers.
Of course, no school faculty, administration, or student body will be unanimous in their personal views, and certainly my kiddo had grievances about individuals or individual circumstances, but at no time did any of us think that we were likely to find a better overall environment insofar as being LGBT is concerned. At home, we spoke often about the welcoming environment, and we counted ourselves lucky.