I believe it uses the same [eventual] execution path (e.g. Code-Security LogOff -> EndSession, etc) as a typical log off, but I am not 100% sure. Trace the execution and see if it does call the same rules.
If it does, then most of these activities are available for you to customize. So for example here, you could change to a different HTML stream of your choosing, instead of the logoff/login screen.