I have been involved in professional motorcycle road racing for 40 plus years at the National Championship level as a bike builder, tuner and sponsor. Most really high caliber riders refuse to compete on road courses such as the Isle of Mann. They prefer dedicated racing facilities that have runoff and other safety considerations because they are riding on the ragged edge and it is just not worth the risk.
Here is an example of racing on a dedicated road race course with my buddy Cory West #57. I tuned for him early in his career and his dad back in the 80’s
https://youtu.be/j5r4Y3l6-nc
Check out my tag line, ponder, then PM me if you wish.