Using Multiple Displays

If you are using a multiple display configuration, Buttery Taskbar will show all taskbars on all monitors when opening the start menu.

However, you can choose to just show the primary taskbar (with the notification tray and all that goodness) via Windows Settings. Go to:

Settings → Personalisation → Taskbar → Multiple displays → Show the taskbar on all screens (Right-click on the taskbar to quickly access Taskbar settings.)