Once installed, timer will trigger to setup and clone user table and initiate process instances to track each user status. If there is any error in the system data, you can leverage the delete all button to remove everything, then republish again.
The update user action initiated many active instance and have only been tested with 100 users so not sure how performance might be impacted when large amount of users are around. The IsMonitored attribute in UserControl1to1 is designed to terminate the listening of the process instance