It has been a struggle that refuses to end. Frankly I am shocked I made the two big drives I did completely without incident before all hell broke loose (Boston to NYC to Albany, then Albany to Syracuse). We went to take it for the alignment (final step) this week only to have a brake malfunction. Next thing you know I am ordering front calipers for both sides. For those keeping score that is a total replacement of every part in the front, rear and emergency brake system apart from pedals and some hard line. Tranny is back up, all fluids are new, all the moving parts up front have been gone through, all new tires (1" size bump), so as of now we are done after we torch off my rear shocks and align it. I may go ahead and redo the air-ride, but that won't keep me off the road.
Looking forward I'm saving and surfing interwebs for the parts I need to build out the kitchenette over the winter, and then an outdoor BBQ tailgate-ish system over the summer. Some time next summer I will make a final decision on the tail bob. If I build a storage compartment under the bed I will make up for the loss of space in the cabinets. Then it's time for twin dirt bikes on the back!
To answer the question:
IIRC the "Rhino Ambo" (Someone correct me if I am wrong here) singled the rear and added a spacer, then had a catastophic axle failure. Not sure if there was a specific incident that caused it, but the talk was that putting all the weight that far out caused the axle to bend and snap. "Belefonte" got singled recently, so far so good! I haven't really spent a lot of time looking into it, but there have been a few in depth conversations on it. One of the main issues you will find is how to compensate with spacers, and find a tire that can support all the weight.