I've owned 15 Utilikilts. No pleat curl problem. Never ironed them.

Here's the secret.

Wash the Utilikilt. Hang it from a shower rod from three Big Box Store plastic hangars with about five clips on each hanger. You can usually buy a bag of extra hanger clips near where the hangers are sold.

Once the kilt is hanging I clip a weighted clip to the bottom of each pleat.
The weights pull the pleats straight AS the kilt dries. If you wanna be super neat you can also hang weighted clips from each of the inside clips too. I did at first but found it wasn't necessary.

To make your weighted clips buy a few bags of those extra hanger clips then head over to sporting goods and buy half ounce fishing weights, then hit hardware for some duct tape. Tape a half ounce fishing weight to each side of each clip. A mindless chore easily done while watching football on tv.

Its simple, it works.

If you insist on ironing ditch the ironing board and iron the kilt on the floor. That way you don't have to wrestle the kilt which is much larger than the ironing board.

Ron