Usually the "Hockey Stick: is caused by the thumb screw not swiveling. A quick fix is replacing the swivel. On Pegas type saws, I carry replacement parts.
I use 3/8" Baltic Birch plywood as the backer stained black with Saman Stain. Water base so pieces stick. The reason I use 3/8" is that the sawtooth hanger works without interfering with the top piece.