True, and that's why I added the caveat that a hem does change the part of the sett at the bottom of the kilt. But, if you're not in a military regiment and can live with a different part of the sett at the bottom of the kilt, the hem itself won't show if it's done properly.

Personally, I think the bigger question is what a 4-5" hem does to the swing of the kilt. If you hem it that much, the proportion of the fell to the total kilt length goes wacko, and the fell is stitched down too far for the length of the kilt and the kilt doesn't swing properly. If the reverse is true and you're letting a kilt down, you can always stitch the pleats down a little farther. But you can't unstitch the pleats if you put a hem in because the pleats are cut out.