Our RV has the following configuration and I am wondering if it is functioning correctly.
(two) Victron MultiPlus II 12/3000 Inverter/Charger
(six, 3 per inverter) GC3 270AH
Victron Cerbo-S GX
Victron GX Touch 70
Is it true that the display is only capable of reporting on one inverter and set of batteries? If so, what is the fix?
If the inverters and batteries are totally independent (not in parallel or multi phase) then the GX device can only interface fully with one system. You can connect a mk3 to USB converter to the second inverter and connect this to the USB port of the GX device for monitoring only in the device list, no control via DVCC. The second inverter runs standalone. You can have a shunt on the second battery bank and this will be monitored and displayed in the device list, no control though.
The better way is to have a GX device on each system.
See Section 4.1 of the manual, plus the DVCC section.