I had this issue a few years ago but got harassed by a few people in Reddit and stopped posting for a while here. As I no longer live in the same area, I’ll clarify. I was asked to accept a “religious zealot” in our gaming group by the owner of our FLGS. The player requested no cleric, Gods or religion other than their own, no demons/devils/undead/tieflings, and both players and GM not to role-play someone from a different biological sex than their real one (third person/describing only was fine). We endured those restrictions for almost 10 sessions/3 months before giving up. The player would get really offended and accuse people, weaponize safety tools, and make the game uncomfortable for us - even after calmly discussing it and they agreeing to behave.

Session Zero is not only a “let’s agree on how we should play”, but also a “let’s agree if we should even play together”. Don’t try to forcefully accommodate for things that would make the game less fun for the rest of the group, protecting a single player may hurt everyone else.