This is my first crack at something like this as I am fairly new to APEX. Thanks for your consideration.
Idea Summary
Add the ability to add a dropdown menu button (menu popup) to a classic report row declaratively. Also, allow the ability to assign each menu item either a process or dynamic action when clicked or selected.
Use Case
I have an example or use case in this stackoverflow question that I asked not too long ago.
Preferred Solution (Optional)
Could implement using a virtual column. The virtual column would have two new ‘types’ under Identification section: 1) button 2) menu button. There could also be a new ‘Behavior’ section added for a virtual column with type button or menu button. Here you can specify / map the process or dynamic action to the button or menu items. As well as, a Server-side condition and Security sections for each menu item.