When trying an alternate Shutdown command for the new buttons feature, the command is not recognized. eg. Set the Shutdown command as: dbus-send --system --print-reply --dest=org.freedesktop.ConsoleKit /org/freedesktop/ConsoleKit/Manager org.freedesktop.ConsoleKit.Manager.Stop still brings up the 60 second countdown dialogue box, instead of shutting down instantly. It's the same for Restart, seems you cannot use a ConsoleKit command. Ubuntu 18.04.1 base (LInux Lite 4.2) xfce4-panel --version - xfce4-panel 4.12.2 (Xfce 4.12)
Whether it shows the 60 second countdown box has nothing to do with the commands are. In the behavior tab of the preferences, the last section is "Session Commands" and the checkbox "Show confirmation dialog" controls if it shows the countdown. It still will run whatever command you want after the 60 seconds are up (or you can disable the dialog by unchecking "Show confirmation dialog" and it runs the commands immediately).
Thank you for your reply.