Assuming you want to be an ULW (sub-10# base) hiker and use a hammock, the "Best" (?) means to acheive the lower weight is to go with down under quilt and over quilt, etc. If you were to do "the full JRB setup", you'll end up with ~4# shelter/bag/"pad" setup.

Not having a traditional pad, what would you do those times when you sleep in a shelter, hostel, or bunk house that doesn't provide a matress?

What would you use to act as your "virtual frame" in your ULW pack?

What would you sit on, or lean against, at a great rocky out cropping with a view?

Maybe a small piece of padding would be used for all three? Like a short piece of a Ridgerest? Or a 3.7oz Gossamer Gear NightLight Sleeping Pad (Torso length)?

Just wondering?