It is possible to develop an extension to do this (or modify the path along path to have another option other than ribbon or snake...)
The problem is that you need to connect the successive shapes along the path which requires locating the tangential point on the pen tip for every subdivision of the path in order to connect the pen tips successfully.
It might be easier conceptually to do it the other way... i.e. make multiple copies of the path around the pen tip shape. Here was some manual playing:
http://www.majhost.com/gallery/ffaat/Stuff/caltips.png
alternately, instead of the straight line interpolation I show connecting the endpoints, segments from the original pen tip shape could be used to connect adjacent path copies.
-Rob A>
I trust that my pictures, in spite of their shakiness, made my meaning clear?
/BP