If you hit aaa to toggle action console… you have every option listed except duplicate or copy bullet
If you try to copy to clipboard and paste, format is gone
You probably already discovered that Ctrl+D duplicates an item but you are right that it should be easier to find on a menu. When you are new to a program it has to be very easy and quick to get to what you are looking for or you might give up on a great program. For someone used to Vim style commands and used to memorizing keyboard shortcuts it is no big deal but we are not all blessed with that experience. I think with some careful thought and minor restructuring of submenus both styles can be served.
We did not add Ctrl+D into the actions menu as in our experience, such “duplicate” shortcut is a typical one, like Ctrl+C/Ctrl+V for copy/paste. At the same time, aa menu is already over-filled with other actions.
We have some good ideas on how to improve the discoverability of actions, but it will take time to implement.