Is there a way to Enable Timecard Notification Emails for a subset of users?

Summary:

Whenever we have historically enabled timecard approval notification emails in our lower environments, it resulted in email notifications sending for all users in our lower environments. We want to only send timecard approval notification emails to one particular supervisor in our lower environments so that they may test approving a time card submitted in our lower environments. Is there a way to turn on timecard approval notification emails for one specific user in our lower environments without running the risk of enabling and triggering email notifications for all of our employees who are setup as users in our lower environments?