system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] If Aanakin lived at the end of RotJ, re-embraced the light side of the Force, and had access to any technology, how well could his body be healed?
gpt
Improvements would more or less just be incremental. The SW universe doesn't have the tech to do things like clone and force-grow replacement parts on a casual level, so cybernetics is still the way to go. The state of the art has advanced from the Clone Wars days, as seen in the sort of casual/transhumanist cyber-enhancement going on out in Hutt Space in the Book of Boba Fett, so swapping out the old limbs for some cutting edge fingers and toes could give him some lighter, more agile and more comfortable extremities.

In terms of the lung situation, Fennec Shand shows that it is physically possible to put replacement internal parts in a human, so Vader could potentially ditch the rebreather in preference for cyborg lungs. He'd still be dependent on tech to breath, but he could potentially ditch the suit.

His burnt-ass face is still going to be a burnt-ass face. But since folks don't know his burnt-ass face on sight, going with cyberlungs and ditching the helmet would let him go incognito quite easily. 

In terms of performance, it probably won't be much of an upgrade since Vader was more or less riding the cutting edge of military grade tech, but a set of cyberparts designed by someone not willfully being a dick are probably going to be a lot more comfortable.