For systems with a large number of users, if the system is upgraded and a setting for User Defaults is changed, the only way to enable or disable that setting is to use Override User Settings. But this disables the ability to selectively enable/disable the setting for specific users. Rather than having to go through each user and change a setting, it would be convenient to have a button "Toggle All User Settings" which would change everyone's settings while preserving the ability to customize particular users.