On Windows 10 (but also in earlier versions, at least for parts of the functionality):

When double-clicking the upper or lower border of a window the window automatically increases its vertical size to fill the whole screen (horizontal size stays constant)
-> Doing this on a CSD window has no effect at all
   (at least dragging upper/lower border does something comparable, though)

A normal window in this vertically maximized state can then easily be moved horizontally *without* jumping back to the old size by grabbing the title bar and moving the mouse horizontally.
-> Doing this in a CSD window immediately results
   in the window leaving the maximized state

A normal window when then pulled from the maximized state on purpose by grabbing the title bar and moving the cursor vertically jumps back to the initial size (however tiny that might have been).
-> Doing this in a CSD window results in an undesired and
   "arbitrarily" increased vertical size