But those two positions are contradictory.

One the one hand saying, we will only acknowledge pronouns that indicate a sincerely held identity, while at the same time saying, no no, it's not about identity at all, it's only about what grammar you want people to use.

I am a cis gay guy, sometimes I use feiminine pronouns for myself, and for other cis gay gays. It's a pretty common part of gay culture. But I am not going to add she/her to my list of pronouns because I don't identify with a she/her gender expression, even though I do use those pronouns. I think it's being intentionally aloof to suggest it's only about pronoun preference for grammatical purposed, and has nothing to do with gender expression. Of course it has something to do with gender expression.

But since we have opened the door to pronouns that go beyond gender expression, into otherkin expression, then there ought to be an option for people to identity as a catboys -- whether it's because it makes them feel cute or because they have some sincerely held identity that they are catfolk. The "it's just a pronoun" arguers are suggesting we just pick whatever pronoun we like people to use, has nothing to do with our identity. Under that paradigm, you ought to be able to pick cat/boy just because it's cute.

Neopronouns are fine, as they relate to gender. But if you open the door to these other categories of identity (which is a reasonable discussion to have that no one has gotten to, because some of the non-gender identites have "pronouns"), you should either open them all or push them all off into a second flair. That is my position. They don't bother me one bit, it only bothers me that some are privilieged while other aren't.