Yes to the small 12" sq solar panel is only for chassis battery and with the battery cut off switch for chassis battery it will still charge, the battery cut off for house batteries has to be on so your BIRD SYSTEM can charge the house batteries & chassis battery.
If you leave you coach plugged in at home the BIRD System
will keep all your batteries fully charged both coach and house.
Look in the Quick Tips and Mod links 1 & 2
plus the new #3
lot of your answers are there.
MAGNUM INFORMATION is in QT's #3.