Sport Mod currently uses the Track A side for crystals. That's in the rule book and is how we ran it since it became an official class. I'm not sure what track Retro runs on but I do know it get's bounced back and forth to whatever track gets done first so that they can finish the racing as quickly as possible.
They *mostly* did not have conflicts at the Nats because Track A and B officials were in constant communication with each other to ensure two people were not using the same frequency. It worked pretty well. I think there was one or two small issues but nothing that wiped out any killer runs or anything.
