To clarify:
You have 4 Battleborn batteries per string of 4 for 48V and 2 strings in parallel giving you a total of 48V/200AH.
The BB's have internal BMS' which will manage the individual battery. They are each independent beasts.
I seem to recall that they had a limit on how many you can put in series, which I believe is 4 BB's.
I do not think there is a limit on what's in parallel. As this only changes the amount of Amp Hours are available and not the voltage, like series.
Theoretically, there should be no problem with adding packs in parallel. BUT THERE ARE GOTCHA'S !
Handling BMS disconnects, interacting with Inverter/Charger & Solar Controller become more important as the battery bank increases in complexity. Over four packs within a battery bank almost demand's a decentralized BMS system that controls all the battery packs with their own BMS'.... This is a Master/Slave model where the central controller communicates with Inverter / SCC systems for disconnecting charge, discharge etc when appropriate as determined by the software and based on what the individual battery packs BMS status is.
PACK = Single Battery assembly. a BB is a stand-alone but when installed into a multiple battery bank, they are Packs within the Bank of Batteries. Each pack requires a BMS to control itself but these cannot interact with other BMS' within the bank. A Master Salve system has the Pack BM<S interacting with the master who is the mediator, controller & communicator of what is going on between all of the packs in the bank and Inverter/Solar etc.