Adjust contour line by script

[maple]

I didn't find any way how to fix the contour line shape around the images when resizing them. If I put 4mm distance around the image and then change size of that image, the distance of contour line is proportionally changing too. It can be nice in some situations, but I need to fix that distance to 4mm. It is annoying to fix that always by hand (F2, shape, edit, contour line check, reset contour line, 8mm size, grow up, ok).

If there is no way to fix it in application, maybe there is a way to do it by script. All selected images, reset contour line and set them 4mm distance (all have rectangle shape). But I didn't find any API to work with contour lines in Scribus scripting.

Any thoughts?