What you find with some docks (I believe possibly this is the case with the Unity one) is that when you right-click on their docked applications that you get a list of windows for that application which are open at the time, and the really good feature that they have is that they have a little "x" close button next to the windows listed which allow one to easily close them without having to go to them. I think that this would be a great feature enhancement to the AO dock's right-click menus for applications.

I initially filed a request for this here: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1627861 But thought I should also do so upstream.

The main reason I thought this would be useful is because I use the dash-to-dock gnome-shell extension and missed the quick ability to close windows when not in the AO, however I think that even for those not using the extension this could be useful as one may have a lot of windows open and may want to close specific ones to specific applications and it could sometimes be confusing which are from which.

Certainly I've had this problem before.