My new understanding is that in a modern Motor Home, unless there is a catastrophic failure of the ATS, no generator power can feed back through the 30a cable from the coach to the house. Likewise, when the power comes back on to the house, the current feeding into the RV's power center will be isolated there until the genset is shut down.
I guess that it's all pretty "idiot proof" these days.
This is precisely as I would expect. I would of course read my owner's manual to confirm all this if I had such a new-fangled thing, but this is precisely how I would imagine such a device would have to be engineered for liability reasons if no other.
Steve