The thing with wearing a cock ring "all day" for me and most men is it gets uncomfortable after a while. Whether it's causing chaffing/skin irritation, or fluid build up in the skin. I feel like (and the gains seem to reflect this notion) you do the work that's causing the gains when you're training. When you're not training, leave your penis alone. I feel no need to 'keep it expanded', or 'heal in an extended state'.