When the thinBackup plugin forces a quiet mode for jenkins the default shutdown message is displayed: "Jenkins is going to shut down". But as this shutdown is triggered by the thinBackup plugin. It would be nice if the shutdown reason is added. E.g. "Jenkins is going to shut down (triggered by thinBackup plugin)".
Other solution is to let the user add an additional general shutdown reason from the thinBackup/backupsettings page.