the only thing I don't like about it is the drive should really be on the rear of the forward part just before the hinge.

front wheel drive, as it must be, is putting the torque way too far from the load, it would be more prone to slipping with high torque because the weight is so far away from it, if the load is too high it would not be able to get moving without traction assistance like throwing gravel under the front wheels, and once it gets going it would be very prone to slipping unless you move the drive to the hinge.

the giant tray back would still lift the whole body even if there was a trannie and extra set of wheels there.