On small screens, at startup the application window can have a bigger size than the screen, while it would be possible to fit the window in the screen
When there are too many dockers, the minimal size of the window can be bigger than the screen
Tabbed docker waste space with duplicating the dock title with the title on the tab but currently one of the two can be used to drag the docker.
the dockers layout manager does not support heightForWidth
The placement of dockers on add is semi-random now. We need something like user-roles which helps determine between which other dockers the new docker should be positioned, ie QMainWindow::addDockWhatever() have to be called in a specific order to get the layout you want and plugins have semi-random loading order
The collapse button is very broken right now, collapsing makes it minimum width, for instance. Maybe we can have a collapsed mode next to left/right/floating/etc (Related qt bug 1858)
If there is one docker that has a maximum width and is docked on the left/right it disallows the docker area to be resized. Maybe we can learn from the anchor layout for that one.