> forget the proj="interactive" for now. 

already there, and now it works.

> And add a vmin vmax in pylab but here vmin and vmax can be dictionary where keys are channel type. How do you like that?

I did not like it because the current handling of vmin and vmax simply makes vmin a negative vmax. In the end you end up passing the same dict / function twice to only use one of them ...
If we go along these lines we will drop max(abs) an use min / max instead.