Honestly, the simplest solution? Add a dedicated profile field for pronouns, like the queer community has been asking for. Creating feeds that are filtered based on pronouns would be so helpful. Could almost use the pronoun labeller for that, but I don't think it has high enough adoption yet.

This avoids the whole "Well if I filter all posts labelled 'penis' because I want to see fewer masculine people, I also filter out pre-op trans women" issue, respects peoples' gender identities, is opt-in, doesn't waste computing resources and is a pretty trivial UI change.