Hi there,
While researching for this feature request, I found out that you could duplicate actions and triggers with Cmd+C Cmd+V, which is very practical. However, I still think a little duplication icon in the bottom, next to the +, would be very practical and good for lowering the learning curve. If you’re afraid of adding too many items to the UI, maybe just an additional item in the menu next to the copy and paste option? Just my opinion, if I’m alone on this one, it’s fine since I know how to do it now.
Have a great day!