Now, if you think trans lives are just an advanced form of crossdressing then dear god you need to educate yourself. the fact the manga is letting you conflate the two demonstrates it is clearly is laundering transmisogyny under the guise of "we made them sexually appealing though!1!1!1!" it is quite the opposite i think this manga would prefer transgender identity never to exist or be invoked from how it already framed kitano, it would spoil the "joke" that Girly has won their affections, it spoils the fantasy thats laid bare by every boy-in-panty shot in here. The plain reading is they are almost exclusively sexualized either as a joke or purely out of fetishization. There was an immediate crass joke about genitalia being incompatible with womens clothing in the first few pages of this chapter, remember? I'm surprised you forgot!
I'm not conflating transitioning and crossdressing, this series has both and right now it's the crossdresser who's catching flak. Deservedly so, he's ignorant and kind of a jerk, but he's also fifteen years old. Getting mad at him is counterproductive. And trying to extrapolate from this one character to the author's secret agenda is just a failure of media literacy. Because you know what's going to happen next chapter? He's going to learn a lesson and become a little less ignorant.
I don't think there's anyone at all who believes Eru is actually correct with his upskirt inference. So next chapter this other guy is going to get his skirt off and, oh, you actually can wear those panties regardless of your undercarriage. Maybe we'll even get a servicey explanation of tucking. Because that's the level this manga is actually operating at. If it's not covering these topics in the same manner you would, fair enough, but that's really leaning into the narcissism of small differences.
There's plenty of problematic stuff going on here. It sure does have a panty shot of a child right there, doesn't it? Gender identity makes no difference in the ethical calculus of fanservice. And the manga's entire premise of a find-the-vagina comedy is utterly radioactive. If anybody want to nope out on that stuff, I can't blame you. But trying to argue that this obviously pro-trans, thoroughly queer, series is doing it the wrong way and therefore contemptible? I can't get behind that.