Played with it some more and discovered something interesting, but it only works on straight horizontal or vertical lines.
After you have created the dashes and expanded them into the little rectangles, (using either Expand or Outline Stroke) you can select them and just set the height (or width) to zero in the Transform Palette, and it turns them into pure strokes, centered exactly where you need it centered.
So that eliminates a few of the steps.
But zeroing the height/width is not going to work for your dodecahedron…
For that…your method works great, and it’s now been officially incorporated into my “Toolbox of Tricks”.
(All other methods are more work.) …