I think what a lot of people forget, or don't even know, is that joker has Arsene as more than a relation to some famous thief for passing lore.
Arsene Lupin as originally written by Le blanc, is a thief yes, he is smart, he has many friends, many talents, and skills in many areas.
But the single most significant trait that makes him so successful is his ability to disguise himself and act as a completely different person.
He even fooled the detective that spent his entire career chasing Lupin and successfully arresting him into letting him go by convincing everyone, including that very same man who knows all his tricks, the "real" Lupin used him for a body double.
Some series like Lupin the 3rd and kaito kid/detective conan have taken this and perfectly captured the intent of this character.
While I have not yet come across a scenario where LeBlanc Lupin has disguised as a girl (i have not read the entire series as the books are frustratingly unavailable my town even at the library.) It is unfortunately also a product of its time which coincidentally was around when Conan Doyle still wrote sherlock.
Kaito Kid, however, has shown several instances of using female disguises and is perfectly comfortable in presenting himself as such.
The whole point of the character of Arsene, therefore, the point of Joker is that you never know who they really are unless they want you to. There are too many masks they can use to their advantage.
On a more personal opinion, I feel like this would be an opportunity where Joker would be able to develop something unique as a persona user. A small degree of shape-shifting could benefit them in both the themes of disguise and gender fluidity.
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