Right now we wait until we're here to check the "shouldAutoSplit" flag on the BalancerConfiguration, and that's after refreshing from the config server. We should check earlier on, in the ShardServerOpObserver, instead, so that we don't spend time submitting chunk split tasks when we aren't supposed to be autosplitting anyways. We should still track the chunk size of inserts in case it gets turned on. Also, since we have a periodic task that's running in the background to refresh the balancer configuration, I think it's okay if there's a short period of time where the setting has been changed but we're not submitting chunk split tasks.