Ray - we never travelled with the fridge on gas, but that may be considered 'old-school' these days. In the past, my biggest concern was the pilot blowing out and wasting propane & $$$.
Realistically, the best thing to do is to plug in the unit while you're loading it up and let the fridge get cold. Once you're ready to roll, unplug everything and hit the road (the fridge will simply act like a big 'cooler'; once you arrive to your destination fire-up the fridge on gas or plug 'er in again. Everything should stay cool & fresh for up to 6 hours so long as you don't go into the fridge all the time while it's off. This was our habit and the milk never went sour....
Now - not actually having my own new trailer in the driveway yet I don't have experience with the new units - will jayco fridge's run off the 12v battery? If so, you're better off using that while on the road, in my humble opinion.
Good luck on the shakedown - I'm jealous! We've got to wait a few weeks yet to try out ours!
3 kids and Buddy the Dog;)
2010 JayFeather 23K
05 GMC Envoy XL