I think that is it a good new feature.
I am a new customer of Fences and a Windows developer.
I think that you can do this yourself.
When you create a new Fence in another Window, you prefix the fence's name with the number of the Window.
In first Window, there is no prefix.
In second Window, you prefix all fences and all icons with "2."
In 3th Window, you prefix all fences and all icons with "3."
and so on ...
That's not beautiful, but this is working.
If Stardock has a better solution ... I am interesting!