Andrew, that is the way I see it as well.
But get the luff curve wrong, and the sail is no good anyway for racing. As a fix, a sailmaker can adjust the luff curve, but it is a fix and not perfect. Max draft and amount of draft will not be as good as a sail designed for the mast.
Jib might be easier/better, if the forestay is is set up with the same bridle lengths and the distance from the forestay-selftacker is identical etc.