I think Meat Roxy has a lot of potential, and his arc that began in the Meat Epilogues could go a lot of really interesting places. Because, as you said, the main concept is "character that is trans, but the author refuses to acknowledge it," which is a really funny and interesting literalization of the idea of ""accidental queerbaiting.""

It's a really, really good meta joke. Just riffing on all the people that say things "how could kishimoto not realize naruto was gay," by making the author literally ignorant of the world he's writing, and the people in it. Reminds me a lot of how (to this day, I guess!) people would say that Andrew "got a character wrong" as if Andrew didn't create them, y'know? Except it's Dirk, who's just really desperately trying to grasp onto his own gender binary by being incredibly weird about his oldest friend. Themes and ideas. Love those.

Anyway, that's all I can say that isn't just recycling the words of people way smarter than me. If you haven't read SpicyYeti's Y12K (and are over 18!), check it out. It's a quite fantastic dissection of Roxy and Dirk's differing perspectives on gender.