Hi Michael, and Pilou. The script has already save me a lot of time. With a very intricate project, where some objects are deeply hidden and there are a lot of snapping points to chose from, it's very convenient to chose a reference Z point.
I often come up with lines that don't join because of different z level. It happens when drawing from top view, and flatten the whole thing often brings the curve to an unwanted z level. Then the script is usefull to bring the curve to the place we want to make an extrusion.
So, some stuff regarding z level like you describe will probably be a nice adition to the UI.
This being said, the UI is already extremely friendly, and a joy to use. Even with hours of continuous work.
Moujiik