Stuff that I’ve seen from people addressing this:

• using -@, -e or -x instead of either.
• picking either randomly, and acknowledging “language limits”. (laypeople way to say “grammatical gender does not necessarily coincide with social gender”)
• picking both and using them randomly
• triggering gender agreement with some additional word, e.g. “la persona no binaria” will always use -a since it agrees with “persona” (person)
• “the dance” aka rephrasing

The -@ and -x things don’t work well when spoken.

Actually the problem is not that hard to solve unless you are trying to be deliberately obnoxious:

You say “no binario\a” depending to the noun it defines. It’s correct to say no binaria because it refers to a person (in spanish persona, female noun).

But it’s also ok to say no binario if you refer to a human being (ser humano in spanish, this one male noun).

I believe they use “no binarie” if anyone’s interested.