As someone in their late twenties who just recently came to understand and accept that I am nonbinary, I applaud you for your acceptance of your kid.
I never fit in growing up and never knew why. Now as an adult I still probably won't mention it to my parents, despite making some significant life changes, due to their proven lack of empathy.
No need to apologize but I appreciate the empathy! We definitely need more parents like you in the world. Though your parenting may be more challenging than some have it, just know the tremendous impact you are making by being accepting of them!
The crazy thing is that I am actually a parent myself. It is very challenging to work towards being who I want to be, my true self, compared to what I grew up thinking a parent should look like. It is especially hard to become myself outwardly, in this stage of life, without feeling like I am putting my needs above my family's. For this reason I again appreciate your views on your kid - I very much wish I knew myself earlier on.
Nonetheless, through the help of therapy, my current focus is to be, love, and accept my authentic self such that my little ones can see an example of acceptance in whomever they want to be. The nonbinary parent role models are few and far between so I must try to be my own!