So many differences among manufacturers. Our Jayco switches over somehow. Not clear to me how it does it but it's wonderful. Winnebago uses (or least to use) as switch.
With the old coach we had, I re-wired to power the radio and its memory backup to the House Battery. One reason for doing it was to not have to turn the ignition key to ACC. Key in ACC makes the power steps want to react to opening/closing the door. That coach did not have a house battery disconnect switch, so I had to add another switch to turn the radio display off when the RV wasn't being used.