Thank you so much for developing and maintaining this; with this tool I was able to get a Silhouette Portrait v1 up and running. The cuts are very clean and the interface is very intuitive!
I did have some trouble getting the regmarks to appear at first -- the installation instructions should be updated to add that to the list of python files to copy. And it would be nice if this was packaged in the extension format inkscape expects, rather than having to copy files over manually. But it WORKS!!!