The option to arrange cards on the corkboard by label is very useful. However I (and maybe others too?) normally use a lot more labels than would be useful to display on the corkboard. E.g. I might have defined 10 labels, but only three of them might actually represent storylines (the other labels might be for documents not representing scenes). It would be very useful if one could define which label lines should appear on the corkboard, in this case e.g. only three of them, so that the other 7 lines don’t clutter up the storyline view.
Cards not belonging to one of the currently display-selected labels could just appear in one neutral line, like it is done with the No Label cards currently (if those cards could still be coloured according to their (non-displayed) labels would of course be the cherry on top).