I do agree that spin and non-spin should be on different courses if at all possible for two reasons:
1: more races - not waiting for non-spins to finish
2: at least the skippers of spin boats understand the limitations of driving downwind. People who do not regularly sail with a spinnaker might not understand the danger of getting in either the blind spot or forcing a spin boat to go over you downwind. That a recipe for disaster.
Ask Jake about Charleston, He knows the danger of this situation all too well.