Trying to stiffen a PBF.
Ben, I use a carbon fiber hollow arrow shaft zip-tied to the leading edge of my PBF. This allows you to fly faster than without one and stops some of the porpoising when you hit full throttle at level flight. The hovering suffers a little though because of the falling leaf syndrome as mentioned in other threads. It does make the PBF more indestructable though, if that's possible.