Rack/awning concept seems like a winner, but I have a couple of concerns. Is the rack high enough off the ground that you will not hit your head when in awning mode? Also, when flipping the rack over what keeps it from slamming over to the other side and doing damage?
The reason for the first question is kind of obvious. Even if it is low and you just plan on using it to sit under with a chair, sooner or later (probably in the middle of the night) you will hit your head.
The second question is based on some tall roll around tanks that we had at work. They were 5 or 6 ft in diameter, had a fixed semi circular lids (thin sheet metal) on the top (back side) with a hinge down the center and a semicircular opening lid on the front. We had a real safety issue because the lids were high enough to be very awkward to flip open. If they guys didn't flip them all the way open it would be on their head. When they did manage to flip one, it would slam down on the other side (both opening and closing) with whole lot of energy, slamming the handles and fittings on the top of the tank, and stressing the hinge. The tank was high enough that you couldn't just walk the lid around while flipping it, so if your cabin is low enough to hold the rack from side to side while you walk around that may not be such an issue; but then we are back to the first question.
(On the tank we put some tabs on top to act as stops, allowing the lid to open enough past center that it would stay open and lean on the tabs, but there was enough leverage from the relatively large lid and the relatively small tabs that this caused warping issues and more buckling; not really an option for your design anyway, just thought I would mention it. Eventually we ended up taking these tanks out of service, mainly due to the lid config.)
Just trying to share some experience in the hopes that you don't have any problems like these.
