I don't seem to have any difficulty with my tie length I was at a funeral recently and tied my tie to just cover my belt buckle.
I find that tucking the tie in the kilt looks awfull. Maybe to shorten it you should tie a knot which uses a little more of the lentgh if you get what I mean. I tie a Windsor knot. Maybe you use a simpler version that takes less of the tie.
I hope this helps