My take on preferred pronouns: "He" is for Male. "She" is for female. If you say you're something else, I'll try not to offend you, but saying an untruth offends me. "It" sounds demeaning. "That" is a singular, neutral pronoun, but it might be fun to try. "They" is used when the sex of the person is unknown ("Someone knocked on the door and ran away. I did not see them").
*** When someone wants to be called "they," I usually know or have a good idea of that person's sex (an uncanny ability developed since I was about two years old). My solution is to try not to use any pronoun for them. I don't have to violate my rules, and I recognize them as a unique individual by calling them by their name.
Basically, if someone wants to force me to use their pronouns, they don't get a pronoun. Pronouns are a convenience, not a right, and it's my choice whether I use them or not.