I stole this off of the American Adventurist website after watching the video on it.
https://adventure-imports.com/product/indeflate/ While most of us have OBA, this could be a really nice helpful solution in airing up. Airing down I prefer my Stauns but it's still very nice. The one thing I did like is if you did get a flat and for some reason your OBA decides to not work this could really help out by pulling air from your spare. If by some reason you have unequal tire pressures this could sure help to equalize everything if your compressor decides to be obstinate.
I suppose the down side is the price at something like $165 and as much as I'm trying to simplify and lighten the load this still seems like a solid piece of gear.