I improved the addon by creating 6 buttons and allowing the user to select the direction to align and distribute.
I was thinking of making a “NetMesh” version, to select two rows of vertices and having the add-on turn this into a mesh between these two points. But this isn't needed after all, because Blender has a “Follow Active Quad” feature within the UV Editor. I didn't follow the directions well enough, which explained why it wasn't working for me.
The 6 button version does work though, and it can distribute great. It is located in the GIT repository on stopstogo.com.
Here is some of my work for the NetMesh version, should I ever want to revisit