Items wired directly to batteries ie: slides, jacks/landing gear, LP detector that do not go thru disconnect switches are wired that way so items can be used while rest of DC System is isolated.
And then there are disconnect switches wired so everything is isolated from batteries.
Disconnect switches are just a means of isolating battery from DC system for storage.
One thing for sure......if disconnect switch is used to isolate the batteries, they will not be charged/maintained by converter/charger when connected to AC shore power source.
How YOURS is wired ?????? Need to trace wiring to know for sure. Then use/don't use as you choose. It is just a device to minimize drain on battery