JMG Don't know which RV you have...many have done various things so your gonna get a lot of idea's.
This is mine...inverter is isolated to supply ONLY the outlet in my entertainment center.
Yes...that's right...what's most important to me...entertainment!!!
Battery #1 -> Cannot be switched to the inverter so its supports coach appliances
Batteries #2 & #3 -> can be selected to coach or inverter
A/B Switch positions;
#1 allow recharging batteries #2 & #3
#2 allow suppling DC to inverter
IOTA Switch "senses" shore power
N/C state allows inverter to support outlet
N/O state when shore power is present supports outlet