I like to work with a reduced composer window, so I only see the video picture on the client monitor, not on the computer display, because of a delay of 1-3 Frames, depending on monitor / breakoutbox / software version.
But since version 8 (also newest 8.4.1) there are some problems when the composer window is reduced.
I don't see the actual picture when trimming / slip&slide or when I switch to a different video track in the timeline (e.g. from v1 to v2).