I added a second switch between the battery and the factory switch. This way when I need to isolate the battery I can, and when I need to cut all power to the camper I can.
Here is the schematic behind my factory switch panel. YMMV....
So, my second added switch is between the 50 amp circuit breaker and the factory (depicted) switch.
EDIT: Sorry, just seeing this is TT. Mine is an Eagle HT fifth wheel.