It does, yes; there’s a foam sheet that extends over the entirety of the main back panel. 1/4″ high-density, which doesn’t sound like a lot until you realize that the pack fits my back curvature exactly…so any padding is more than enough.
The hip belt is, indeed, lovely. It’s also 1/4″ high-density…and it’s conically tapered to sit correctly on top of my hip crest. Straight and/or narrow belts never fit me well, so John built this one to my specs and measurements. It’s also removable in case I need to strip this down for summit use, or in case I need a different belt for one reason or another.
I do use it year-round. I try not to be on hard trails on the hottest days, though.