I would doubt that any solar, whether thru a 'plug' on your RV, or directly wired to the batteries, would have anything to do with your 12v disconnect switch, since it's purpose is to cut OFF power TO the 12v Fuse panel, which would have nothing to do with incoming Solar amps from it's Charge Controller, which is wired directly to your battery bank.
'14 Thor Palazzo 33.3 compact diesel 100k+miles since '14... US, Alaska, Canada...
AND a '14 Gulfstream Amerlite
AND a '07 ForestRIver Rockwood