Yes, you don't want to go thru the "OFF" position instead. I've never heard about problems passing thru "1+2" to get to "2".If you want to go from bank 1 to bank 2 the best pathway is through BOTH. No drop out of electronics and no blown diodes and the resultant transient to house loads if the alts still flows through the battery switch.
"Make then break" is the rule, right?