I have. First, I own a slingcat that has a spring loaded single lever. The rubber is attached to the tip of the lever. When you draw out, the lever is moved up to the upright position, against the force of the spring. When you shoot, the lever is lowered and the ball flies safely over it.has anyone made a custom with flexible forks that would bend on the draw and bend on the release so as to impart more energy to the projectile?