@shroomie Frankly the Toriel bit is approaching fanon but either way, that's my point. If Kris was transplanted to our reality they'd obviously be trans because to be where they are they'd have had to transition, but within the text they aren't because they didn't. What I'm talking about here is that the trans experience necessitates transition, a transgression against cispatriarchal social norms. Within a fictional setting where those norms don't exist, and someone really can just spawn in being non-binary, trans-ness isn't a concept that applies. That's also my point with Undyne and Alphys, if they existed on Earth they'd be queer but because within the Underground queer people are treated as straight, their fictional relationship is culturally closer to irl straight pairings than irl gay pairings.
My point is that UTDR has a lot of representation where the character in question is technically gay or trans but not a lot that reflects the experience of being queer.