IMO PT is being too much of a purist for that. You still need to buss some of your connections, and the monitor's shunt is still there with all the negs. (Don't forget to remove the neg grounding wire from the neg batt post and now put it from the frame to the outer end of the shunt with all the other neg wires)
The usual small parasitic loads are with any inverter draw when it is off and you just count that in with them. To get a no load on the battery bank, just undo the single fat wire on its neg post from the shunt.
You can also put your new deck-mount converter in there (with a 120v supply) and use the inverter's Dc wires since they both want short fat wiring. (That is what an inverter/charger does too)