Kryptonite U-lock rattle stopper

My Kryptonite U-lock is mounted inside of my bike frame with the supplied bracket holding the lock in place. Several times the lock has made its way out of the supporting bracket and dropped on the floor - often whilst I am riding at full speed. Whilst the lock hasn't yet hit a car or taken-out another cyclist, it is only a matter of time. To try and stabilize the lock I have produced a very simple part. It clamps to my seat tube and pushes down into the Kryptonite lock. My lock no longer has an