I sent Jay Glaser and e-mail and this was his response:

The battens should be just tight enough so that there are not any vertical wrinkles coming out of the batten pockets when sailing.

It turns out this is fairly tight.

Too tight and the sail will look like a hungry dog with more shape at each batten and less between.

When inserting the battens make sure the forward end is as low as it can go in the pocket so it is pushing on the lower forward bolt in the plastic protector.

Sail fast,
Jay Glaser

I'll be looking at people's sails this week at GC. I came here with a list of questions and so far I have gone through a couple of them and people are very willing to help.