JayC This is calculated based on your max discharge rate and the the percentage to get down to, in your case 12%.
If however, there is PV generation, requiring inverter capacity for DC->AC conversion, this might affect it. Alternatively, sometimes SOC values are inaccurate.
If you find the target SOC was not reached, what some WW users do, is to create more than one smaller export schedule, with a small 5-8 min gap or so (to account for overlaps), and make use of the lower SOC condition to trigger it if above a certain percentage.
That mechanism seems to work quite well.
