Interestingly that is very similar to the set-up I've been mulling over for my fj60. I like the idea of adding suspension points on the B pillar to support the front on the bed.
I made a similar but much simpler set-up way back when I had a 4x4 Hi-Lux. It was basically a reconfigurable bookshelf looking thing with open back and front that could have a section or two easily added on to the side(s). I could change it up whether the camper shell was on or off, could be used inside the truck, on the tailgate, on a table, etc...
I'm thinking I could make my own new design with some guidance from that website. I wonder what they're using to bind it/hold it together?