

I think playing with the body and especially the mind (through eugenics, genetic engineering, or any other means) is as big of a nono in the Star Trek universe as fascism, due to trauma from the eugenic wars (you know, when Khan and his ilk fought baseline humanity).
Body modification enthusiasts, transhumanists, furries, and anything like that are probably treated with fear, loathing, and disgust.
Heck, they won’t even treat baldness despite being perfectly able to fix it if they wanted to, and they don’t seem to have made any effort to cure aging, despite being able to cure almost everything else; their life expectancy isn’t much higher than ours, when it should be much higher.
You want that kind of thing try Iain M. Banks’ Culture series. Even more freedom to live your life however you want, the only limits to body modification are your imagination and some of the laws of physics (much less than in Start Trek, though), and people live to a healthy 300 or so, throw a party, and die in their own terms because they’re done, or curious. Or do not, no one is forcing them, they can keep on living if they want to.
Heck, one character used to have about sixty penises all over his body, just for fun. No more, though, even with four hearts at that point it was starting to get difficult to maintain an erection at the same time in all of them.


Yeah, try it on someone else’s junk.