Ok, that seems to work.
I learned that line width is normally automatically derived from nozzle diameter, for all machines types (top level UI or machine config). You can indeed set line width from the top UI dialog by overrulling the automatic value set. Then all other parameters are derived from this value. The parameter is stored, so kept upon next use of Cura.
Thank you Neo!
gr. Marco
P.s. it still seems a bit artificial and limited to make this difference in user interaction between the various ultimaker models.