Currently when you create a New Reminder Notification, you have the option to send that reminder to:
Dependent Task Assignees
We have a need to send to the Project Sponsor when a task completes. We use the project sponsor field for whoever submitted the original issue.
After a particular task, we would like to be able to let the sponsor know that their deliverable is complete and where to find either final files or final URLs, or even to send them a survey. But due to the nature of some of our projects, there may be additional tasks that do not complete for days or weeks later. So adding the Reminder Notification to the issue isn't ideal since the issue doesn't close out until all the project tasks are complete.