The disappearing shape looks like a layer order problem in that example - SVG does not specify depth, so it might be easy to have shapes present but out of order, depending on the SVG file and the interpreting program.
Any experience in the Silhouette software, but some knowledge of SVG and raster/vector issues and the information in (excellent selection of sample steps!), it looks like it might be possible in AD with a little more preparation work to simplify the situation - in effect, to create vector silhouettes for Silhouette Studio.
