I just tested the module, and I think what you are saying is right.
If I put it in N mode on the steering wheel, I immediately felt a whole lot less stiffer ride than it was before the module. So it seems the ECS module adjust the stock comfort / sport en N mode suspension maps.
If I put everything on softest setting in the custom mode, the ride is even more pleasant!
Difference is very noticeable! The sharp edge is off and it feels more like how my Clubsport felt. Very cool gadget! Love it!
Only thing it lacks is making the automatic connection within the app. Have to manually connect.
What firmware are you using? Clearly in my case (firmware 1.0) it always obeys the command I gave it, either through the app (ecs) or the steering wheel button, custom mode switches to N mode, suspension becomes hard, does not retain ecs option.