Hi Mike yeah the Blend command is currently limited to only being able to make a blend between 2 edges at a time, so you'll run into a problem if you've got something like one edge trying to map to a fragmented set of multiple edges on the other side.

There are a couple of things you can do about that. If the side that has multiple edges has each small edge touching smoothly to its neighbor, they can be merged together with the Merge command:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#merge

Then once you have merged together the fragmented edges into one long edge you can then use the long edge for making the blend.

The other option is that you can take the long edge and dice it up into smaller edges by using the Trim command - inside the Trim command use the "Add trim points" button which will let you click some points on the edge for the spots to cut it at. For this method you want to dice the long edge up into segments matching the segmentation of the other side.

In v3 I do want to work on improving the Blend command so that it will be able to use a sequence of edges on each side of the blend instead of only one edge on each side.

- Michael