The way Qt handles windows on Windows has not been overhauled in a long time. 

Current assumption is cleaning up the window handling will help us fix a couple of Windows bug which are related to window repositioning and resizing which is a topic which comes up again and again.

In addition to that an overhaul might enable us ot create windows with a "glassy background" as can be seen in Windows explorer and the Windows settings app if transparency effects are enabled.