Its not a matter of "lets look whats the worst situation possible guys". Of course given the choice at gun point i would rather have sex with a post op trans than have unprotected sex with an AIDS female...
But if we go that route then we can do it for everything, i would rather have my pinky finger cut than my whole hand. Does not mean i want my pinky cut or i wouldn't be hurt if it happen.
No matter the reason, if its mentally or physically, a client should have the right to know it, just as a female escort who is HIV positive should never work in this business...
To me its unethical, thats all.