the ocs i have that mostly aligns with what you asked you be either lily, dagon and hael, in order lol

lily not so much actually because she's transfem in a more "close to irl" way, since she's trans in the gender sense, but i thought i'd still mention her because you asked about procedures and she does take a in-world equivalent to hrt and has had tail reduction surgery :3

dagon doesn't really see himself as either angel or demon, but he's also not suuuuuper dysphoric about it so he never seeked anything procedure-wise in that regard. except for boob removal LOL. the little dysphoria he still has is about his hooves and while there is surgery to make them look more like feet, most doctors would refuse to do it without tail removal (the excuse is balancing issues) and his tail is VERY important to him, so he wouldn't do it. he might shave his horns from time to time (horns in inferna work kinda like nails except with nerve endings :p) but he wouldn't be worried about keeping them that way, he'd enjoy the different stages of growth and then shave them again once they reach max size lol.

also there's hael, who is a trans demon buuuuuuut ended up drafted. he also ended up being bought by dagon, who actually believes that the draft made a mistake with him and tries his best to be accommodating and let him live as a regular person in secret and without getting either of them in trouble. dagon eventually manages to get him hrt-equivalent meds that would make more hair grow on the end of his legs, and make horns, tail and ears grow :p. For ppl assigned angel at birth(?), however, due to their regen, they need to remove those parts continuously and wait for regrowth each time, while taking hrt, to see effects. (this is a bit hard to explain, hopefully it makes sense?) i think he'd only feel safe enough to get surgery for either wing removal or feet reshaping once things start getting more chaotic in inferna and the pet system start to crumble for real, so it would take time.

(if anything about hael doesn't make that much sense, read his page https://s4dsqu1d.nfshost.com/inferna/canonprofiles.html , it should help, i think)

also to answer some more about procedures specifically:
-there's hrt for "both sides" that work on horns, tail, ears and certain places of body hair development, ether by slowing down/shrinking or making it grow. for growth, you need to have regen powers + keep cutting the limb off
-they're pretty advanced medically so most surgeries you can think of probably exist.
-ppl assigned angel at birth usually have regen powers and ppl assigned demon at birth tend to have enchanting-like powers, that's the only thing you can't really change :s
-well, technically you can't change height too drastically either, but you can change it a bit to make dysphoria related to it more manageable