Shimming up the back of the wing would decrease the incidence. If you try it, put in a couple of clicks of up trim as it will tend to put the nose down, which is what makes it penetrate better. Once you get it up a ways trim it to suit yourself. Shouldn't affect the hand launch at all from the way you've been doing it. This is how we got penetration in the wind when we flew rudder and throttle only. That was a few years ago.