You mention running it while on the road.
There's no problem in running your existing A/C off your generator while on the road, it won't use very much gas. At 6824 BTU, the Dometic is quite a bit smaller than your existing 13,000 - 15,000 BTU A/C (depending on your model year). It's also significantly more expensive.
If your existing A/C is inadequate, I'd consider adding a second, similar (possibly smaller) unit for a lot more BTUs and less money. My understanding is that these (or at least some) will also fit the standard 14" x 14" vent hole.
I think you'll find that, by running your existing A/C off the generator while on the road, you'll have a better experience while parked since you won't have a large heat load to overcome.
You don't have the restrictions the Dometic was designed for so why limit yourself?
Here's a relevant post from another forum:
https://www.escapeforum.org/forums/f...ing-20371.html