In the stepdown suites, concurrency_sharded_with_stepdowns and concurrency_sharded_with_stepdowns_and_balancer, the toggle_feature_compatibility.js workload is initialized to run for 5000 iterations which frequently times out the suites on the Windows DEBUG build variant after 6hrs. It was also found that this workload with the stepdown configuration causes spurious failures, and hence was blacklisted with SERVER-31884.

For other suites, like concurrency_sharded* we are going to reduce the number of iterations this workload is run so it will finish in a reasonable time.