Im not sure how it is at other Track Day Events, but if a certain car/driver is causing major issues at GT Track Days, it is handled by the Event workers and or Orginizers.

As far as being held up by another car on the track at a HPDE Event at Road America, come into the pits, slow down, go right back out PROBLEM SOLVED....Its not that fucking difficult. The godamn track is 4 miles long.