Here is how I would do this, which might be a method within your Revit realm if it has similar capabilities or components in place.
We use an application that makes sure the user's %appdata% Revit addins are up to date with addins at a network repository for such. The application also retracts retired addins and makes sure some addins are always present. The users's desktop manager runs this app in a headless mode prior to starting Revit. Therefore a user's %appdata% Revit addins are always up to date with the repository. It executes in a split second. Users have no clue this is happening and its all Black Magic to them anyway if they did, and if you are old enough to be their parent, then it does not matter what you say. One of these addins, "BeThis", is attached to Revit's DocumentOpened event. BeThis sets the user's Revit workset how they prefer and it hides whatever custom discipline Revit ribbon Tabs the user could care less about, much like an AutoCAD Workspace setting.
The point being, this BeThis addin, which executes upon every DocumentOpen event, could easily "phone home" with the users' Windows login name, Revit user name, Revit file being opened, machine ID (maybe not necessary now, you have the login name), date and time etc. etc.. It would keep a running log wherever you like of who's on first base. This feature could be silently deployed and retracted using the above described approach.