Depends on who is making the kilt. The "casual kilts" that Lochcarron make, for instance, are based on four yards of cloth, are knife pleated, and machine stitched. They won't make them to any particular pattern (stripe or sett), they say because of the reduced amount of material. What they will do is to come up with some regular pattern that approximately pleating to sett.

Now, I don't know what their construction techniques are, or their justification for this. But when I hand-tailor my four yard box pleated kilts, I always pleat to the stripe (unless someone tells me they prefer pleating to no pattern). I don't see how box pleats v. knife pleats would make a difference here. So I don't quite understand.

I don't have a lot of direct experience with the casual kilts offered by other firms, so I don't know if they will pleat to stripe or not.

Aye,
Matt