Jax is a good transfem representation, just not the kind you are used to, and I am tired of explaining that, so I wrote an essay.
I am going to use they/them pronouns for Jax, simply because it is a grammatical tactic used for omitting the subject's gender, which is my intention here.
Meanwhile - yes, I somehow agree that they are a poorly written character, and the show could have shown us more, although the signs that are present are crystal clear to someone from within the transfeminine community (not to be confused with the queer community in general).
Gooseworx had publicly stated multiple times that Jax's character was supposed to be her self insert - but not of herself as she is, but rather of the worst case scenario of what would happen if she had not transitioned.
The usage of the word "boymoder" in one of her posts in regard to Jax is self-explanatory to chronically online transfems like me, but if you are not familiar with it - it is used to describe a person who, irl, hides under the façade of presenting masculine, while maintaining a female gender identity, usually either kept to oneself or online. If that is supposed to be the case with Jax, do not expect them to go in front of everyone in a swirly skirt and dance happily. That is also why their identity is never clarified directly as "trans woman (full stop)" in the show.
The maid outfit acts (which are HORRID to capitalize on by the way) also tell us a lot about our boymoder. Zooble, the only other person under the trans umbrella present, is probably also familiar with this running gag, hence they decide to put Jax in this outfit. Here is the Maid Outfit 101: it is highly sexualized/fetishized, mostly within the online "femboy" community; it is mostly associated with early stages of MtF transition; and, most importantly, it is commonly considered tacky and cringe in general. That is why Jax reacts this way while wearing it.
As we all have noticed, throughout the entire show Jax displays multiple instances of misogynistic behaviors, most probably rooted in the denial of their own gender identity. They even make fun of Zooble simply for falling into the bartender stereotype, the only thing that would have been the cherry on top would be calling them a "theyfab". This type of attitude is overpresent in the online radical transfem communities, which are fueled by self-hatred, hatred toward women, and hatred toward other groups under the general queer/trans umbrella (trust me, I have seen takes such as "trans people are women" while lurking these spaces).
During the ending, when Caine shows the circus members the lives of their IRL counterparts, Leeroy (Jax) is portrayed as male - which means that they still have not come to terms with transitioning, or that they still do not have a good ground to start their transition. Mind you - since one of Gooseworx's posts talks about what would be their chosen name, we can take an educated guess that Leeroy is not it.
To conclude everything: Jax is a tragic character, their tragedy being not transitioning, which ultimately leads to their abstraction; a cautionary tale if you will. They are not an embodiment of perfect, divine womanhood everybody expects from trans women, but merely a "sad loser," someone lost in thoughts and haunted by them.
Feel free to discuss, correct me if I'm wrong, and add anything you feel like you want to add.
