Yes boys and girls, you REALLY need to carry a spare...

Bigfoot Florida told me if I manually to raise our Entegra 24B to raise it by the two left side jacks, or the two right side, or the two front, or the two rear, but do not raise just one corner at a time. I guess you could twist the frame.
I guess if you were to carry a spare in the rear you probably should have a mounting bracket that fits into the 2 inch receiver hitch, mines rated at 7,500 lb. towing 750 lb. tongue weight.