Realize it's not for everyone, or anyone other then myself, you wouldn't be wasting the first few feat with cage and seats, as its triple service as in seats, dinette, and fold down bed, crew cab, not so much. My van has a payload of 7900lbs, will end up no where near this, hopefully, and will be off-road capable for my vision which is limited by having a 12' long living space on the back and tall enough to accommodate standing in comfort, with cabover. Not by the capabilities of the van itself. All with a158" wheelbase,
Put 12' on the back of a crew cab and I believe that's a greater limit to any off-roading , again my experience only. Here in B.C. any of the big 550,5500 aren't capable of going anywhere I like to go off-road. I consider them very limited, highway and Fsr only, get into the mountains, with cross ditches and washed out narrow overgrown roads, good luck, I drive these roads daily for work and at one time drove a van crummy bus, realize it must be different in other areas regarding off-road situations.
Don't know if everyone is familiar with Ujoint Van conversions, or Clydsdale, but with a front axle upgrade, some of there builds I would say are off-road capable. I was impressed enough, time will tell. Checked into local legalities regarding adding seats and was basically told do what I want from the girl behind the counter, as registration doesn't list seating capacity? Will be doing more research on this.