The cute girl theory of transfemininity explains my transition as well. At age 16, I didn't want to be a girl or woman, I wanted to be an anime girl (or perhaps an anime trap, aka anime trans girl), and that was the main source of motivation behind my transition. I never really had gender dysphoria before transitioning, but I was lonely, a bit autistic, and wanted to occupy a social role that doesn't really exist. You see a lot of this type of trans girl in lesswrong circles, while the HSTS/non-online/older trans girls are in their own world
I wonder if we could do a big ealla-style survey of trans girls to find out more about their sexuality, relationship to their body, anime, programming, joint hypermobility, etc.
One simple observation about the HSTS cluster: it seems to me like they try to be "actual" women, without as many caveats about gender nonconformism or strong ties to transfem culture. I'm an AGP/anime-girl trans girl, and many "mainstream" trans women seem kind of alien to me, in the same mental category as cis women