Normally I'd be where you are. Encouraging people to temper their expectations. Because it always sucks if you're super excited for a work you think is trans-coded to suddenly whiplash and disappoint you, because yes, most gender bending works aren't written with a trans audience in mind. Especially manga.
Kaneko Naoya as an author is the
exception in a major way. Their last manga, TS Gakuen, had some heavily trans femme coded characters. First mildly but then
overwhelmingly going towards the climax. It's not at all weird for us to expect that trend to continue. (I'll elaborate below)
Without further ado, there's
many signs in this chapter that Ren is trans coded:
1. Her expressing the idea of "Having a girl's body is every guy's dream right?". That's a familiar sentiment and one frequently expressed by eggs. Show of hands if anyone else read the top panel of page 7 and reflexively winced in recognition.
2. Bottom of page 9, Ren outright admits to being an avid consumer of gender bend material. That's what they meant by "that genre". It's actually not too uncommon for Kaneko-sensei to include a wish fulfillment character like that, usually in their oneshots. The two page oneshot that later grew into Vignette Witch actually had a gender bender fan who was happy to see her new witch form.
3. While it's true that a surface reading of page 13 could suggest that Ren is in it just to wear a skirt and that's where it begins and ends... she outright says that it never felt enough to just crossdress. Also outright said she doesn't see anything
wrong with crossdressing and doesn't necessarily fear being judged. But there still needed to be more to it; she needed to be a
girl in a skirt. I realize that's still subtext as opposed to text, but that's Japanese character writing for you.
Still, with the full context (and knowledge of the author's prior work) I think it's pretty safe to get invested in Ren as representation. When, again, normally I'd be encouraging people to do the opposite and temper their enthusiasm lest they set themselves up for disappointment. But that certainly didn't happen last time with this author.
A good way to put it is that if most MtF genderswap manga leaves trans femme readers with two leftover college cafeteria chicken wings that were already half-cold by the time we got them, TS Gakuen gave us a whole rotisserie chicken by the end. Even if it's a supermarket rotisserie chicken and not some Michelin star meal, eating
very well instead of barely eating at all is not what any of us were expecting. Just speaking for myself, Kaneko-sensei has earned my faith in whatever he's cooking with Vignette Witch.
Finally, the skirt thing can sound like a kind of a silly thing to get so hung up on, but it rings
really familiar to me as well. It can very much be a little things like that which puts a hairline fracture in the egg. The thing that really gets into your psyche like a stone getting into your shoe.