But isn't the whole thing asking someone to accept/endorse a different worldview? Is that really a tiny favor?

What? I hate surnames like 'Bill', 'Chuck' and 'Dick' and wouldn't want them for me, but if some Charles explicitly asked me to call him Chuck, I would call him Chuck, I'm not an asshole.

Calling the man "Muhammad Ali" didn't mean you had to convert to the Nation of Islam. Just call someone what they want to be called. You can do that without any endorsement of the reason behind their request. A "different worldview" doesn't give you permission to be an asshole.

I don't think that's an accurate metaphor, given names are historically pure labels with no external semantic meaning. The direct comparison here is that a man could asked to be named "Karen" and that doesn't to me seem to cause any philosophical conflict. (Some people might not want to do it, but that doesn't mean they have a legitimate reason). (Although there must be some limit here as well, eg "the great and majestic Philip, he who we all aspire to be" surely must be agreed to be unreasonable.)

The difference with pronouns/gender is that they depend on and proclaim external facts. ("She" is used for women and by going by she, I am a woman.) And by asking someone else to say that I am a woman, then really, aren't I forcing someone to change their definition of "woman"/"man"? Why do I have the right to force someone to do that?

Out of curiosity, if someone asked you to use plural pronouns for them, would you? (This is hard to ask in English, because "your" is used for both singular and plural subjects, and "they" has also commonly been used for both singular and plural as well, but imagine) What about pronouns in other languages? Do you really think that in communication, the other speaker shouldn't have any say in any of this?

I don't appreciate comments that suggest that someone you're discussing is an "asshole" for doing something you disagree with and don't think that contributes to the conversation.