I'm not very knowledgeable on gender politics, but I do have a good friend who has identified as non-binary for a number of years. I've always thought it was more profound than a person having certain hobbies, therefore they're non binary, but maybe there's a range (genuinely don't know).
I''ll use female pronouns as she has said she doesn't particularly mind what people use, and she is biologically female. I tend to use male or sometimes neutral pronouns irl though.
My friend presents in a very androgynous manner and her name isn't gendered. I've had mutual friends who have met her for the first time (and spent hours in her company), who have later asked me her sex and gender.
She has a vagina, but has had her breasts removed and her chest reconstructed as a male chest. I think she intends to have hormone therapy if her body shape becomes more feminine as she ages. I believe she is pansexual or queer, but has not actually told me.
Pronouns have changed over time (originally feminine, then masculine, now whatever).
She's more comfortable with herself than she was growing up and seems much happier generally.
I appreciate gender politics are a hot topic on here and I have no interest in debating it, but I have no issues with accepting my friends' identity. It is significant to them and i am just happy that they're now happy with themself.