I'd like to be able to smack my ESC key and have it close the currently active lister. Of course, if another DOpus-related child window (like the Preferences window), is active, I'd like that closed instead.
Is there a way to do this?
Create a hotkey for Esc which runs the close command:
Note that you have to use the menu shown to set the hotkey to Esc; if you push Esc instead it'll close the hotkey window. 
Awesome. I didn't notice the drop-down. Thanks, Leo!