Thank you dBC,
that's what I was doubting, I have tried the "max current" option of the car but indeed it does not work.
What I would like to do is to limit the absolute maximum peak, so to a given fixed value (e.g. 7kW), not flexible.
Unfortunately my wallbox is fully digital, it can be configured to do this, but only by an installer (need special admin right for the config APP).
I was trying to avoid paying 150€ for changing a simple setting in the wallbox (probably 2 minutes work), but it seems that I have no choice.
I think that still for such an expansive car, this flexibility shall be included.