We are able to add the injected separator to both ribbon and menus.
Notice that we are able to set visibility at separators.
Separator in ribbon
To add a separator in ribbon, use this command between your buttons or menus. You can add it in an individual module at the end or in the beginning, or in between buttons.
As an example, here is how it looks in ribbon:
Separator in menus
To add a separator in a menu, this command must be used between two buttons in the menu (note that it is an injected feature):
This is how it looks in a menu: