As I have limited viewing space I like to move a few key boxes off to the side so that I can keep them visible and not interfere with my workarea. The Pages and Select Element features are nice to have open at all times; I would do the same with the properties box if it were able to leave the workspace.
The annoyance results from attempting to do anything outside of ForeUI as these boxes refuse to give up their foreground position. If there were simply a setting somewhere that would allow me to uncheck this focus-demanding aspect my workflow would be simplifed and my screen a little cleaner.