Trying to follow how this all works, so more questions!
So ? you can use the Iota Li dongle with a build your own bank but not with a drop-in? because you have another way to prevent over-voltage or you have your own settings?
I don't have a Victron monitor (Trimetric here) but how does it shut anything off?
You add your own BMS ( explained here somewhat)
https://bmspowersafe.com/en/technology-en/pcm/So your BMS is not the same as what you get in a drop-in so you can get away with using the Iota dongle?
Itinerant1 has something else in his mix ISTR "EMS" to go with his BMS that he uses for his settings? What do you have?
Do you lose all 12v in the RV if the protection method shuts down what? Yours shuts down the charger but not the batts?
Note--I do see that your battery cell is "3.2v nominal" so that explains why all those Li batteries say 12.8v on them (4 x 3.2)
Enough pestering for now! Thanks.