the more heat you can make ( and then exchange- fan kits!) the better the fridge will cool
I use dc when driving, I use AC on shore power ( you are paying a fee for the space and the energy, so you may as well use theirs).
both the ac and dc use a heating element which is not as effective as the lp gas
and we use the LP when boondocking or stopping mid-drive
( I once forget when a stop for a minute turned into a 6 hour stop- which about drained the coach battery and blew a breaker as the current draw raises when the voltage goes down from the draining battery)
some make a shield to run propane when driving- I consider this stupid- esp when the gas fill and fridge are on the same side.
the fridge should be able to hold temp on DC, in addition to fans kits ( on the external fins and an internal fan to move cool air inside) when rotate the blue freeze packs from freezer to fridge door.
and have a wireless thermometer to monitor temps without opening the door