Will changing clocks and re-running the scheduler affect already voice tracked shows?

No, changing clocks and re-running the scheduler will not affect voice tracked shows, provided you do not unschedule the hours that have already been scheduled.

When you modify a clock and re-run the scheduler, only newly scheduled hours will use the updated clock settings. Any hours that were previously scheduled will remain unchanged, which means all voice tracking work done for those hours will be preserved.

To ensure voice tracked shows are not affected, avoid unscheduling hours that have already been voice tracked. As long as the scheduled hours remain in place, the voice tracking will stay intact regardless of any clock changes you make.