Asklemmy

As an enby myself, I’d probably default to they/them but try to sprinkle in gendered pronouns when I saw them presenting more one way or another.

Depending on how close your relationship is, you can ask them if they have certain times that they prefer particular pronouns or not.

If someone tells you they don't care about pronoun usage, believe them. I'm nonbinary and don't care what pronoun people use for me, because I identify as both male and female. Most people default to "he" for me because of my beard, but others use "they" because of my proclivity for wearing skirts, nail polish, and lipstick. Rarely I'll have someone use "she" (or I'll use it myself), but ultimately, I'm just a person who exists outside of the gender spectrum (or right in the middle), and pronouns are just a grammatical tool to save time, so I prefer that people use whatever comes most naturally to them.

As a nonbinary someone who accepts any/all I would say whatever comes naturally or is your preference. I've identified as agender since I was young and so personally I don't really like defining myself to other people in terms of gendered language. I would say if someone tells you their pronouns are any/all to trust them that they are actually fine with that.