I'll be honest, the NB route won't have a ton of new content. I'm not non-binary myself, and this game is, at the end of the day, intended for binary trans women. There are also a ton of non-binary identities, and I can't include more than one, since I'm not confident in my ability to represent it well, it would take a lot of time, and I'm personally just not as interested in writing it.
I will do my best to include a they/them pronouns option. I'm trying to figure out how this will work since there will be problems. For example, with she is vs they are, it's not as simple as just changing out the pronoun itself.
There would also be some other changes here and there, like people not calling you a girl, small dialogue variances, and NB Ethan will think of themselves differently in certain scenes.
Sorry to get your hopes up! It's mostly there for small changes here and there to help accommodate more people, not an entirely different route. Depending on development time, I might not be able to include NB content in the game at all, although I will try my best to.
TLDR; Incredibly unlikely chance of demigirl or demiboy