Just broke down and added the 2nd AC unit in bedroom on our 37" Jayco Designer. Trip to LA and AL with 90 degree temps convinced us. One of our major issues was the noise since the AC sits right ove...
Both of ours are ducted, in our current rig, so you plan works great for us. In our old 5th wheel the front air was not ducted. So it did not work well in 90* weather to cool the TV area to a comfortable level for us. But may be good for others.