You might also wish to consider a device called a Trick-L-Start.
Since it appears Winnie did not install a BIRD (BIdirectional Relay Device) on your Bago,,,,, This device provides the "Reverse" charge function.
It hooks to your isolator relay, with 3 wires.. one hooks to the CHASSIS side, one to the HOUSE side and the 3rd is a ground.
This should let you run Radio in ACC as well.
And glad you liked my description of the toggle switch.. Many motor homes come with that switch already installed.
Home is where I park it!