Great video.
One of the best sessions I attended at PNW Overland Expo this past weekend was tire pressures.
The Gist? One size doesn't fit all. Just because the guy in the Tacoma is taking his tires down to 20 psi, it makes zero sense for the Wrangler JLU or full sized RAM to do the same. You have to know the specs of each tire, the actual load on each tire (front and rear), and the recommended cold inflation pressure for each tire. You have to dig, but most major tire companies have buried on the websites (or will send it to you on request) the research that they have done for recommended tire pressures for each traction situation for your specific tire based on load. There is no logic way to generalize about air down pressures.
This Aussie presenter reports that he drove across Africa in a Land Rover and aired down exactly one time.