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).
Because not all the words that are gendered refer to a single gender. I understand when we change the last vowel to an e to add a non gendered version of a word that has both male and female forms (e.g. nosotros/as, spanish for "we", would do great with a nosotres). But when the word itself is already non gendered (as persona, which although is considered female, refers to any person of any kind, because there is no male alternative) I don't see a reason to do it.
There is no discrimination in referring to someone as a persona, since there is no "persono" word, so saying persona no binaria will offend only who wants to be offended.