Hi,
I'm not filing this as a bug since I'm running OpenSUSE 42.3 with KWin 5.8.7 but I want to know if this has already been fixed:
When I enable "Display window geometry when moving or resizing" and then resize windows the width & height are not updated when resizing the window but are displayed as "$ORIGINAL_VALUE+DELTA" (i.e. "Width: 162+37") where $ORIGINAL_VALUE is not updated while resizing the window - which makes it hard to resize the window to a given size,