The tapering of a batten will control where its drive point will be, as well as controlling its deflection load. Good batten design takes these two things into consideration. You can taper your own battens to suit these two controls just by sanding it fairly evenly on each side with an orbital sander. Battens in different parts of the sail have different drive points and different deflection loads. Lower battens have the drive point slightly forward than upper battens.
Lower battens have a lighter deflection load.
The variation in deflection load will range from 2.25 to 3 pounds for the lower batten to 3 to 3.75 pounds for the upper batten. My H14T battens are as follows. The Percent and Load numbers are the key. I suspect that the deflection loads could be lower for the light winds of my local lake. Even down to 2 pounds.