Solar charging 12v and 48v lithium banks through a manual transfer switch

[Atomvoyager]

I posted this on another forum but no luck yet. I'm installing an ePropulsion Navy EVO 6.0 electric outboard on a monohull and need to charge both 48v and 12v lithium house banks off the same 12v solar panels. As with a diesel, the engine battery will only occasionally be used while the house bank will be used all the time. The eProp 175AH 48v battery has a switch on its case that needs to be powered on whenever it is charged or discharged. The eProp dealer suggested running the solar to a boost controller direct to the 48v bank and then charging the house bank through a 48v to 12v converter. But to avoid it's power drain and conversion losses and to provide fail-safe redundancy I think the simplest solution is to use an 8 terminal multi-pole transfer switch of the type used to select between generator or shore power to supply the boats 120v circuits. In any case we will have a 48v to 12v converter to charge the 12v bank from the motor when it's in regen mode.

The three 12v solar panels are connected in parallel rather than series because of shading issues and would go to a common input on the transfer
switch. On one of the output sides it goes to the house bank using something like a Victron 100/30 charge controller and the other output position charges
the engine bank with a 48-volt Renogy Rover Boost controller.

https://www.amazon.com/dp/B088PHPHZC?th=1

The eProp supplier said I need to isolate the grounds as well on the 12v and 48v charging circuits to avoid "problems". I'm assuming this switch with one input circuit of two conductors and two conductors each for two output circuits will do the job? The single switch is to avoid the problem of two separate switches that could allow the solar to go to both banks at the same time if they were both accidentally left in the on position.

A similar setup was described in the latest Good Old Boat magazine but did not identify the switch used or how it was connected. Any ideas if this is a workable solution or if there is something better to use?