From a lore stand-point, that's super cool. As a trans person based on our perception on gender and sex, it's cool to see someone who's build a whole ass universe where gender is mostly up to the individual themselves, rather than up to the general perception of society as a whole. I'm a trans woman, and although I live in a pretty liberal country in Scandinavia, there are obviously those who would always proclaim firmly that I'm a man who can't accept myself.
And although trans protagonists are becoming far more common, especially in the interactive fiction scene, I always feel like the protagonist being trans is either just handwaved away as being okay in the setting without any further explanation as to why that's the case, or them being trans just isn't mentioned at all which to me does take away some aspect of what it means to be trans. I'm by no means saying everything should have a big philosophical debate about gender and sex, but some games which even features sex scenes be they explicit or fade to black, often don't have the protagonist mention that they're trans to the love interest at all, yet they go on to have sex without it ever being brought up before or after the sexual encounter which honestly just doesn't make sense.
I can handwave away that all the love interest are magically attracted to the protagonist regardless of gender, but even if they are attracted to their gender, that doesn't automatically apply to their genitals. Some lesbians are more than happy to date trans women regardless of if they've had surgery or not, while some just aren't attracted to male genitals and therefor aren't interested in dating a trans woman (Which is completely fair, genital preferences aren't transphobic) and obviously that goes for gay guys too. So I feel like the protagonist not talking with them about it prior, and it never being brought up after the fact, makes the protagonist being trans feel disingenuous if that makes sense? Obviously we want a setting were our identity is accepted, but it's naïve to not at least make it a topic of conversation when it comes to relationships, because even if the setting is completely accepting of it on a social level, it can still very much make a potential relationship incompatible.
Even in a society where we're fully accepted, it's absolutely still something that's important and needs to be mentioned as a part of the story, because otherwise what's the point in making the protagonist trans? At that point, it just feels like it was added for the sake of being added. We like to pretend that we're no different than cis women, but at the end of the day we are different. Sure we're still the same in terms of our gender identity, but being trans inherently makes us different on a physical level which is something I feel like should be addressed more, especially in games that are romance heavy. It doesn't have to be the main part of the plot mind you, but an offhand line of dialogue where the protagonist tells the LI that they're trans would be enough if that makes sense? Like that I feel like when the LI is fine with it, they've accepted who we are, and established that it doesn't matter to them, which I feel like is a super important thing to establish in a relationship when one of the people in set relationship are trans.
Sorry for my massive long ass commentary on the status of trans protagonists in interactive fiction, it wasn't ever intended to get as long as it did xD. I mostly only ended up going on that tangent to show how much I appreciate your setting, due to how open they are as a society when it comes to identity and biological sex. It's refreshing that there's a deeper meaning behind why being trans isn't a big deal, and it's written in such a way where having those casual conversations about it aren't necessarily needed. It feels genuine, and not just like being trans is accepted just for the sake of making it an option, without any thought-out reason behind why it's accepted the way it is.