Well, the one benefit I can think of is that it would be a heck of a lot easier for me to lay out the pleats!

However, if you mean benefit for wear, no there really is none. It would just be for historical accuracy, if someone really wanted a kilt made just like c. 1800.

Without the tapering, I'd have to make the whole kilt to your breach (hip) measure, since that is the widest part, and you'd just get some bunching at the waist. How much would depend on how much smaller your waist is than your hips.

Tapered pleats allow for a much better fit, and a much better hang. I'll always taper the pleats to fit your measurements, unless someone just really wanted an untapered kilt, in which case I would warn them, like I just told you, that it would not fit as well as a tapered kilt, and if they still wanted it made that way, I'd gladly do it for them.

I'd probably also suggest they have me leave off the straps and buckles and just wear their kilt pinned on, or with a belt.

Aye,
Matt