Never forget that almost every guideline and most court rulings in Germany's medical system does not have a concept of being non binary. Transition is always seen as something binary, with the goal of getting as close as possible to the "other gender". Almost all of the guidelines health insurances use word it that way.
Do not tell your doctors that you are non-binary. Don't do it. You are allowed to lie, you need to lie to get gender affirmative medicine.