Yes that way or you could UVMapper to export out the UV's then add all the bones and groups you want to the head create your morphs then export out and load it into UVMapper again and import the saved UV's back to the figure and save as new figure. Should load as a new morph just fine.

May still be easier to use something like Zbrush or Modo or what ever Modeling app of choice. But my first morphs were done like that because I had better control than with magnets.

I wish I could find the original thread on how I learned the trick. It was sometime in 2001?