I would ask yourself why you are bothering with the insurance at all?
Unless it has changed, track day insurance has an excess of 10% of the cars value and does not cover third parties. It is basically only an insurance against your own mistakes (or stupidity). Of course mistakes happen but if you have invested time learning to drive on track. i.e. CAT Driver course or similar, understand about adjusting your tyre pressures for grip etc, and drive at 7/8 10ths instead of the limit, you should not need insurance. I drive reasonabley quick on track (991.1 GTS) and also compete in Sprints and occasionally Hillclimbs. I take the view I drove it there and need to drive it back. I have had slides but I understand how my car behaves so they don't panic me.
Most of the incidents I have encountered on track days are generally due to people who are idiots and think the track is exclusive to them.
If you want to reduce the chances of an incident then another option is your choice of track. Goodwood is very fast but has a closed pitlane with fixed session time. That separates people on track and stops you spending too long on track at once. You don't learn much going round in circles. You need break time to reflect and improve.
