I would appricate two soft limits:
DESS min SOC
Why: leave capacity to prevent grid consumption in the morning
How: DESS schedules not to discharge lower than this SOC.
What: If consumption is higher or PV lower than expected, the limit is not respected
DESS max SOC
Why: leave space in battery to avoid selling on negative prices
How: DESS schedules not to load higher than this SOC
What: If PV is higher than expected or consumption lower than expected, do nor respect this SOC
Rule: 100% >= DESS max SOC > DESS min SOC >= min SIC >= 0%
With 8ct/kWh or even 0ct/kWh selling price and around 36ct/kWh buying price, keeping (configurable) 5-10% room for uncertainty of prognosis would be great.
In my case (PV: 8.5 kWp PV, battery: 56kWh, consumption: 12-30 kWh/day) I could avoid consumption at high prices and selling at negative prices completely.
BTW: thanks a lot for DESS and the open source Venus OS. Definitely your USP for the inverters.