Related question. I do mostly shore dives, and have been gearing up on the tailgate of my pickup truck with my single-tank backmount rig. Since the singles have a boot on the bottom, they stand up nicely, and hold the entire rig easily. I recently picked up a manifold, bands, etc, and sent a pair tanks off to the LDS for a viz and to have the valves replaced to turn them into BM doubles. Turns out the tanks need to be tumbled, so I won't be getting them back for a week or two.
Since they won't have a boot anymore, they won't stand up by themselves. Is it going to be annoying to gear up at the truck with the doubles? Not too many people shore dive with doubles around here, but I've seen a mix of folding tables, pickup truck beds, using picnic tables, etc.