Jake,

I use the hole to tie them. More than half the time I forget to loosen them after a sail. While I understand the theory, my sailing is not at a level where I notice the difference from varying batten tension. I did, however, replace my battens with a set I got from Randy Smyth. They really seemed to give the sail a better shape. When I swapped them out, I noticed the effect of rolling the sail with the battens not quite parallel. The old battens had taken on a sort of a twisted shape. Don't know if that was affecting performance, but now I'm pretty careful to be sure and roll the sail with the battens parallel to the roll.