I have two varieties of kilts in the closet. Longer for winter and shorter for summer. Indoors both get the "top of the kneecap" hem setting. This works best for sitting without messing up the pleats when I put an ankle on the other knee. But then outside and the cold winter wind is making my knees too cold it is easy to slide the longer kilts down about two inches and get my knobby knees out of the wind. Back inside, I hitch it back up.
My upper body garments are all made to work with the lower waist position so it is no issue if more of the kilt is covered when I have moved the kilt up.