Dimension, or caliper, for your technical drawings. Made with geometry nodes, so completely procedural.
You can also use it instead of the measure tool if you want your dimensions to be visible in the render.
Snap the 2 target empties to anything in your scene, you can also make them children of vertices. Rotate the base object to change the direction in which the extrusion happens. The text tracks the camera which you set in the modifier.
Do you think it can be improved? Let me know in the comments.