I think it's worth thinking about the use of labels in this game, rather than just going 'It's just a smut game, stop getting triggered so much!' Yeah, it's a sex game that primarily uses language as its building blocks, with transformation and exploration as its major themes. Fen's games attract a disproportionate number of trans and queer folk to them for a reason. It's worth thinking hard about terms that would be derogatory irl being used casually within the game.
Fen himself kind of swung and missed at this early on, when he dropped the term 'tranz' into the intro to refer to a dicked female PC. That was clearly intended to be his catch-all phrase for TiTS peeps with a less than vanilla gender/sexual arrangement. The problem with it is firstly it's really lame, like most of Fen's titles for stuff (he himself acknowledges he can't come up with names worth shit). Nobody was going to use it unless forced to.
The other issue with it is larger, and encompasses the phrase 'trans' too. Trans literally means transitioning, or transitioned. It's perfectly legitimate to use to refer to people irl who developed a different gender to their sex. In-game, Kaede is a perfect example of this. But is it really ok to use it to refer to someone who was genetically engineered to be born with both a functioning pussy and cock? What of someone like Syri, who kind of just got mashed up as a result of an accident? What of gender tourists, of which the PC can easily be, who could chop and change their genital arrangement as and when they wish?
The TiTSverse allows for far too many different scenarios for 'trans' to make sense - and that's just for humans and the human-adjacent. Almost all the alien races have some sort of exotic sexual/gender arrangement as a trope that makes a mockery of the term. Now, we can imagine a future where 'trans' has been used enough that its original meaning has been lost and has now become a blanket term for people who are basically non-binary. That's probably indeed what Fen intended with 'tranz'. But honestly, the term isn't descriptive enough! If I describe an NPC in TiTS as trans, what does that even mean? If I describe them as a futa, or a maleherm, or a trap, you know exactly what I mean, as uncomfortable as it might be to read.
Which brings me onto the second point, which is a more difficult one to make, but one that must be made nonetheless. These terms are loaded irl, and for many people - I'd even suggest the majority - that's exactly why they're hot. I love using dirty language in TiTS, I love crafting a scenario where I can call the PC a little sissy bitch, or allow the PC to run their mouth off about the big dicked supposedly dominant sort-of-lady alien they're topping. Dirty talk is great, this is where it belongs, in a fantasy game, and it's by definition impossible to create using politically correct language. You get a little thrum from those phrases being used casually.
So, ultimately: This to me feels like a circle that can't be squared. It's not ideal that we use derogatory gender labels in TiTS by any stretch. But replacing them all with 'trans' would be worse. The actual, baseline problem is that our own society hasn't evolved to a point where judgment-less labels that we could use for all the many shades of sex and gender exist. And so we must use the ones that appear in porn instead.