When roofing, I've made a hook from a steel coat hanger and attached it to my air hose with a small radiator hose clamp. I hooked it to the top of the panel and let the hose hang down the outside. Then unhook and move to the top of the next panel when necessary. It also helps to have a hook on the nail gun to hook to ladder, panel, or anything within reach. If right handed, the hook should go on the right.
I agree about the roof jack, but 50 years ago on fresh plywood, the roof was easy to walk on, until it started raining. Wanting to drive the last few nails into the fresh plywood before pulling a tarp over it required driving a few 8D nails in part way to stand and hang onto. That new plywood became very slippery in the rain. This wasn't OSHA Acceptable either, but very necessary at the time.
Charley