The reason for mounting the propane tank on the rear is to make room for a generator on the front wye . The weight of the two tanks will go rearward and the inverter generator would take their place up front. Tongue weight would not be much increased if at all . Just thinking about it right now, but wondering why you don't see that set up more often.I don't want to mount the genny on the ass due to its weight and bouncing back there.