When my mom was going through her multiple doctor appts, many of the forms asked what she wanted to be called. Everyone looked at the form and adjusted accordingly. Seems to me that’s a win-win for both the medical place and the person.
Don’t all places do something similar?
At school I called a student, “Blueberry” because that’s what he told me he wanted me to call him. Makes no difference to me. I have all kids tell me what they prefer if they have a preference. I also tell them they can call me whatever they like, and as long as they don’t use “idiot,” “moron,” or something equivalent we’ll get along just fine.