I have a dual monitor setup. I basically have removed all the tools from the main screen so it maximizes the viewport. I can undock the panels easy enough, but I would like to be able to easily arrange them in a second container window so that I can organize them in a way that makes sense to me. Once you undock the windows, it doesn't look like you can recover the tabbed arrangement. I'd like to able to stack them in another arrangement according to the way that I like to keep things organized. A second window would allow you to organize all the tools the way you want, and keep the maximized viewport to work with.