I have seen the SVGs attached to your original post, which actually behave as described in the first link I provided. (Videoscribe will generally draw uniform/basic stroked paths but not tapered or paintbrush style strokes. Videoscribe regards paintbrush style strokes and other tapered strokes as though they are color fills instead of stroked paths, so they are not "drawn" by the videoscribe hand by default, however they can be "revealed" by any transparent uniform/basic stroked paths that you include to reveal your color fills. In SVGs that contain no uniform/basic stroked paths at all , the color fills and paintbrush strokes will all simply appear or in some cases be lightly outlined by the drawing hand and then appear.)
You said " this morning I did a very basic test using different width profiles, with just one path in the SVG, using the pen tool. It drew correctly in Videoscribe. " That's what I was curious to see.
I'll probably make a 2016 update of the SVG tips thread in case it does not explain these topics clearly enough.
-Mike (videoscribe user)
it should work something like this (see attached svg and video)