What if (unironically) ugliness is used to justify the firing? "Person X is ugly and ruins morale. They also happen to be trans, but that's not why we fired them. We fired them for being ugly."
Edit: To clarify, you'd be able to get away with this at Hooters or a strip club or if you're making a movie or whatever. Probably wouldn't work for traditional businesses.
What if (unironically) ugliness is used to justify the firing? "Person X is ugly and ruins morale. They also happen to be trans, but that's not why we fired them. We fired them for being ugly."
Precedent should work fine for this https://www.businessinsider.com/how-can-hooters-hire-only-women-2015-9
Edit: To clarify, you'd be able to get away with this at Hooters or a strip club or if you're making a movie or whatever. Probably wouldn't work for traditional businesses.