Measurement of element coordinates

My question is about he method of measurement of element coordinates.

Following minimal example describes the problem:

1. Create a rectangle at the coordinates X=0, Y=0 (by entering the values in the text fields)

2. Change the line width.
The coordinates of the rectangle are based on its outline. That's why the
coordinates change from X=0,Y=0 to X=-3.65 Y=-3.65 (for example).
It would be preferable to base the measurement on the center of the
line, to retain X=0,Y=0.
Creating a complex drawing with many elements and exact positions
would be much easier this way. An Inkscape option which activates
this feature is my requested feature.