What you are talking about would actually be a vang. A vang pulls down on the boom to control the twist in the leech of the sail. They can also be used to bend the mast and depower the sail. Since the AI doesn't have a boom, no vang.
Generally speaking, once a sail is furled beyond 15% the shape is terrible. It tends to make the sails very full in the middle and tight on the foot, which is the worst possible shape for big wind.
Remember, when its windy to pull on lots of downhaul. This will bend the mast and open the top of the sail. With a square top main and no boom, you should try to trim to the top and middle of the sail and not worry as much about the bottom otherwise you will close the head and stall the flow at the top of the sail creating a ton of drag.
Good luck with your rigging. You should post up the results of your experiments, I'd be interested in hearing how it worked.
Experience is what you get when you don't get what you want.