Multiplus II: I don't want to use battery power on AC2 dump load

I have a MultiPlus II 8000, MPPT RS450/100 and 18 x 370w solar panels. I have a 8kw lithium battery bank. I am not allowed to feed into the grid. I don't have a ET112 energy meter installed currently. My whole DB board goes through the system. Critical loads on AC1 and 2 geysers and a small stove on AC2. I live in SA and we have blackouts twice daily for 2 hours Which uses about 30% of my battery bank (maximum).

When the geyser and stove switches on the solar power is usually sufficient but sometimes there is a shortfall and is supplemented by the battery instead of the grid. What are my options here?

1) Is there a way to program ESS / another assistant to ensure that the battery is not used for AC2 loads?

2) Do I need to take these loads off the AC2 and bypass the system and then use the ET112 Energy Meter to power these extra loads with excess solar power and grid only.

A best practice and long term solution answer will be appreciated. Thanks.