As far as resting goes, I'm not sure that it makes any difference to the mouthfeel or moisture level, but I do prefer a hot steak to a cold one and if I rest it's only by accident.
There is something to the change in flavour profile after a prolonged rest (overnight).
My reheated steaks always seem to have a more pronounced smoke flavour than the freshly cooked ones.
Mind you I've never tested it scientifically, so it could simply be due to my own senses being dulled to smoke flavour when I've just been cooking in a smokey environment, whereas the next day I get to the steak without exposure.
You tend to reverse sear though. I've seen in videos claims that there is no point resting after a reverse sear. The rest has already occurred either in the sous vide or in between the slow and the sear.
I have no idea how valid that is but it seems to makes sense.
For the smoke thing, I've always assumed it's because I've been dulled to it. I notice it particularly with roasted lamb.