[Full writeup here.]
To finish the adapter, place the lens inside the wide end of the connector, and adjust to get the tilt desired. To fix it into place, simply tighten the screw clip. To adjust, loosen the screw clip, mess about with the lens position, and try again.
The design works because the mount is rubber, and the lens size is just a little less than the diameter of its mount. The lens sits comfortably in the mount, and the adjustable rubber gives it room to move when you want to tilt it. The metal clip (when tightened!) ensures that the lens can be held in place. The field tests that I've done so far have shown that the lens is indeed held pretty solidly in place.
The main drawback is that it's not as interactive as plungercam 1, and it takes much longer to set up a shot. On the other hand, you can definitely use it for time-lapse captures, which was a goal of mine.