Even a blind hog can find an acorn under a oak tree once in a while. After reading post #9-10 and 11 in https://www.homebuiltairplanes.com/forums/showthread.php?t=2855 , Anti Spinning Strake , maybe the engine cylinder covers on the side of my cowl will have the same effect in spin recovery. I did design the size, shape and area location of the rubber for better spin recovery. Loved the spin recovery of my Falconar F-12 , easy in either direction and easy out. Easy to stop the spin in a desired general direction. It had a huge rudder with a lot of the area below the stab.