Thanks, if I DO have 4 BMS across these parallel banks, and I pull the load from the + and - of opposing banks, will these BMS be a limiting factor on the amount of current I can pull from, going to the Quatro?
It depends on how you do it. You might run 2/0 (or whatever is appropriate) from the battery/BMS to a four post bus bar (may be five). Then run a 4/0 cable (again, whatever is appropriate) from the bus bars to the Victron Quattro inverter. I don't think that there will be room to run all four cables from the four batteries directly into the Quattro.
It's likely a bit more complicated than that since a shunt would need to be placed downstream of the bus bar where the four batteries tie into.
Battery negative -> BMS -> negative battery bus bar -> shunt -> common negative bus bar -> inverter
Battery negative -> BMS -> negative battery bus bar -> shunt -> common negative bus bar -> solar charge controller
Battery negative -> BMS -> negative battery bus bar -> shunt -> common negative bus bar -> other stuff