If you have the room, you can afix a eye hook under the center of the Vanessa as close to underneath the center line of the dowel as you can that no matter how the rig shifts the CG line still hangs straight down. Due to the design it will have to be slightly fore or aft of the dowel centerline but you can adjust for this by measurement and it will be a constant fore or aft amount. It will also be a very slight amount if you do it right and this isn't meant to be a 1/32" tolerance device.

I just try to adjust the loops as much as I can to get a straight hang, or twist the rig as needed until it hangs "straight" sometimes it works, other times, not so much.

whit