How to Identify FRS Users?

Summary

FRS will be replaced by Web Reporting Studio Effective 21B

Content

Prior to our go-live we trained many users in FRS.  At this point we think, but do not know that some of them do not use FRS.  We've also added new users in the interim.  With the imminent transition from FRS to the new Web Reporting Studio effective with 21B is there a way that we can identify any FRS users to insure that they are using WRS?  We can send out emails and place updates on the home page, but at the end of the day receipt of an email doesn't mean that it's read and the suggested actions