.......same here. The top batten can support the extra roach and with partials towards the bottom you can shape your sail better in my opinion.
Many classes that use full battens are raced extensivly, and they have certainly learned all of the tricks. When you see full battens on and AC boat, we can say that they are slow.
Tapering to match the sail is one trick. Sail Delmarva: Search results for battens
. It is easily done, but most sailmakers don't do it because it takes time and is best done after the sail is delivered and set. The leach was sagging 6" to leeward before; it was hard to look at. Without full battens it was a throw-away.
Full batten sails:
* cost more
* flog MUCH less
* catch on back stays
* generaly hold shape better
* chafe more, but only on the batten pockets, which can have guards added
* set better in the absense of heel
* generaly last longer
* are heavier
* don't tweek as easily in light air
* don't flop as much in light air
* are easier to flake
* are harder to store
* have unique hoisting problems (batten friction) when over ~55' luff
Thus, they suit cats very well. Monohulls I cannot speak to. A compromise (a few full battens) seems rational.
That batten taper subject remains valid.