I use trade mode and have not been able to figure it out yet. From what I have been reading it’s only related to green mode. To fix VRM forecast deficiencies using logic on the Cerbo itself.
For example, forecast says solar delivers 2kWh between 14:00 and 15:00 resulting in SoC increase of 10%. Consumption forecast was correct but solar forecast was incorrect. So target SoC is reached too soon at 14:30 and the sun is still shining.
With DESS, the remaining (probably another 2kWh) solar will feed in to grid. Whereas the correct solution is to continue charging the battery to prevent feed in, possibly having to buy it back later.
The new reactive strategy fixes this locally on the Cerbo. I think… 
It is mostly based on this work: [DESS HACK] Unexpected Bat2Grid and Solar-Feedin. (Green Mode)