My RT had a 3-way fridge; 120V AC, 12V DC & propane.
For me, propane & 120V AC would cool the fridge and 12V DC would try to maintain that degree of coolness. We would switch to 12V DC when driving.
My new fridge is 2-way; 120V AC & propane. I will run it on propane while driving on long trips. I guess I could run the generator while driving on long trips........ that's kind of noisy though
The safest way to travel with propane is to shut it off at the valve on the tank. You have to do that for some tunnels and when traveling on a ferry etc.
Always make sure propane appliances are off when refueling.