Reminds me of a joke from the late great Mitch Hedberg.But if you concede that optimum sound quality requires turning an R-2R or multibit DAC on "a few hours" before listening isn't that really an argument for leaving them powered up all the time? Several hours warmup is not really practical for many, if not most, people including me; certainly not for every listening session. When I used the original Schiit Modi Multibit, I left it on all the time (as Schiit recommends). I just got the Denafrips Ares 12th-1 this week and am leaving it on all the time.
I like baked potatoes. I don't have a microwave oven, and it takes forever to bake a potato in a conventional oven. Sometimes I'll just throw one in there, even if I don't want one.
Because by the time it's done, who knows?