The thing is, you have a waist measurement and a hip measurement. So does your kilt. When you put it on and it fits at the waist and fits at the hips - that is the height it is supposed to be! Moving the kilt up higher will bring the hip measurement (which is larger) up to where your waist is (which is smaller). This does not lead to a well fitting kilt. If it is too long, that is a problem of the hem, not of the waist.

Any kilt can be hemmed. I wear a MacLeod hunting and defy anyone to tell me how deep the hem is, without taking it in their hands and looking.

Will hemming a kilt make a difference to the swish? Yes, it will. I would argue that the swish is in fact better.

Think grandfather clocks. There have been pendulum clocks in use for a lot longer than the modern kilt. Why have that weight at the bottom (like a hem)? I give you no answers, except to say 'pendulum effect' and that Google is your friend.

If it were me, I would have it hemmed. That way you can choose the exact height you want.

Regards

Chas