If the manufacturer had put the front axle behind the back axle, you would not have this problem.
This is most likely a classic example of the salesman telling the design guy what the customers are looking at. High published empty pin weight makes smaller truck owner move away from these trailers. So they design them to shift the weight back when empty. That works fine, unless you use the same frame on a toy hauler where you add 1,000 or more to the rear. And now you have the OP's problem.
Looks like you would have to travel with no water or fuel until you get close to your destination. Or maybe empty water tanks and water jugs up front to help offset the weight of the SxS in the rear.