I think it would be a good idea to be able to put the Progress Indicators windows available also as a pane in DOpus (Preferences). You can have tabs, if multiple progress indicators are started. It would be easier to keep tracks of copy progress while continue to browse files, instead of having multiple windows open at the same time.
That's been discussed a few times and might happen in some form one day, although it's not completely clear how it would work best (e.g. when the window with the panel was closed while progress was still ongoing).
I used SpeedCommander and they have the progress indicator in a pane (without the ability to close it), but if we close the application, we had a messagebox that tell us the there's file operation in progress.