A bit of clarification,,,,,,,

My last post reads like $*^#

What i was trying to say was---

If you know what the waist measurment is and you know what the hip measurment is, it doesn't matter very much that the pleats in the back are tapered over a longer distance than those on the sides.

To do a quick lay-out check, hand pleat and pin your fabric on your lay-out table. Pin at the hip and also at the top of the taper. Then draw your slope line with chalk.

Now you can adjust the taper so that the measurments at the slope line will be correct for the waist. This will also give you a chance to see how the pattern of the stripes will change and require extra care to get them even, on each side of center.

I assume you will not be trying to create a full hand-sewn kilt. And I assume you are not using Barb's method of pleating and tapering one pleat at a time.
Because this may be one time when laying out all the pleats first is preferable.