Kind of an aside but if I were building this camper from scratch I would delete the 3 way and put in a compressor run "Fridge freeze". Mine pulls 40watts when the compressor is running , is a top loader but puts out a huge amount of cold and can freeze the whole compartment in a handful of hours. My 3 way running on propane here in the desert will freeze in the freezer section but struggles to make the main compartment 30-40degrees lower than ambient. It takes forever to get cold in the main compartment. Like 2 days sitting in my garage prior to a trip to get the main compartment cold. The ambient for me is often in the mid nineties.
The front loader is much more convenient that the top loader but that takes a back seat (for me) WRT making things cold or really cold.
Just my opinion. Also thanks for all of the replies to this thread, it is helpful.
steve