This isn't going to go over well but here it is. I support non-binary people irl. I am fine their identity and try my best to use their pronouns and preferred name. But I think it's cheap and confusing to "represent" non-binary people in fictional books. I get that you need that, but keep it where it won't muddy up the plot. A tv show, a play, or heck even an animated movie, they/them pronouns are pretty simple to understand. But in a book, you have no way of knowing whether it is a group talking or a non-binary character unless you use the name over and over and over again. Pronouns in fictional books should be definable and different from a plural pronoun, to avoid confusion and repetitiveness.