It's an interesting idea but I'd imagine it would be impossible to create a law to stop someone performing the acronym fetish.
The Genspect conference fallout is a good example of why.
Ideally it should be obvious that the dress choice in relation to the occasion, and whether it's in keeping or incongruent, (not just the fact someone was in a dress) is very much a part of it.
Grayson Perry talks about his own thoughts on all of this in his autobiography, including why he wears dresses with lots of fluffy layers to hide how much he's enjoying being out and about in public dressed as his alter ego, Claire. There are pictures on the internet of him in schools, at Buckingham Palace etc. Arguably his dress choice is a particularly clever one because he's created a character who wears these type of dresses, no matter what the occasion.
It would be impossible to legislate for it. It's about understanding it and then mitigating for it, through spreading that understanding and using current laws effectively. We've already got a legal framework in the EA to sort out the difference between the sexes, with access to single sex spaces etc.
People with this acronym are very adept at moving around wherever they want to go. When they step forward to talk about what it's all about, that's got some useful info in it. But the guardrails need to be robust beyond laws in order for that kind of conversation to happen. Public shaming used to cover it but that's been eroded by all the Be Kind stuff, to the point where sometimes those doing the public shaming don't get heard at scale in the way that they intended it to land. The infighting that has resulted from the Genspect stuff is a good example of this.