I recently watched TNG The Outcast and I thought it was really well written. Some people call it a cop out for not directly tackling homosexuality. But I think Star Trek does its best stories when using a storyline to reflect a real day to day issue through metaphor. I think it could be interesting to see a story where an individual identifies as feeling trapped in the body of the wrong species. And wants to b change their appearance. Rather than coming out as trapped in the wrong genders body.
If such a comdition could ever exist I wonder if doctors would diagnose the patient nuts. Or sympathise and help the person transition. Haha imagine a ferengi wanting to be vulcan