Re: Propane hook-up.
I carry two 20-lb tanks on the tong. One is ties to the trailer regulator, the other is my standby. I use the standby tank for my grill. I have a short hose and a long hose for the grill. Sometimes I remove the tank from the trailer, sometimes I don't (that's what the long hose is for).
Disadvantage would be the unexpected loss of the furnace in the middle of the night, compared to an auto-tank-switch.
2009 17' Plan B