Will do Don, it's not really that complex when you keep the second pack completely seperate with it's own Charger/Inverter/water cooler and BMU/BMS/ECU (Coming form a stripped down 2012 that got a new battery and charger). All you have to do is bridge the 2 inverters on the 360V (fully charged) and make sure to close the relay in between BEFORE turning on/off either pack to prevent those nasty error codes.
It will become a one seater though by removing the back and passenger seats to make sure I don't go over the max payload but that's fine since it's my 2nd car, I've got a 2018 PHEV for the rest
Both batteries will have to be charged seperately which is not a problem at home and gives me the opportunity to still use L3 charging on the primary battery only when they're both empty. And to top it all off I'll install a diesel cabin heater in the back so that every single watt is dedicatd to driving during those cold Quebec winter days.
I'll keep you posted, if anyone has any tips or advice please share.