QPrintDialog: Do not forget settings when using CUPS

QPrintDialog "forgets" any changes made to the default settings. It would be nice to have a possibility to save any changes made to the defaults, like e.g. duplex printing, or the currently selected printer. Right now it takes me six clicks in QPrintDialog if I want to print Duplex on a printer which is not the default selection (two to select the printer, one to expand "Settings", one to change to the options tab, one to activate duplex and one to print). In principle one click on "Print" should be enough.

Please see also https://bugs.kde.org/show_bug.cgi?id=180051