I wanted to decouple some facets, so I can move them around independently but they share common vertices. Is there any way to split (uncollapse) the vertices? I tried doing a split facet at the joint, but it did nothing…not surprising since it’s already an edge.
Instead of first trying to duplicate vertices then move them, just use the Facet/Move (or scale or copy or mirror, etc…) command with the Copy facets button, it will duplicate the vertices.
This also works when working with the vertices themselves, all vertex edit commands (move/scale/rotate) have Copy versions as well.