Wow! I love Fences! What a great idea! Here's what would make me buy the pro version:

If the fences could "minimize" in a way so that only their labels show on the desktop. This way you could mouse over or click on the label you want, and the fence would appear with your shortcuts inside.

If a fence could contain folder contents, such as documents or downloads, so that you could point a fence to a folder and have everything inside available as icons.

Holy Toledo, this is how Windows should have been designed from the beginning. Genius work, Mr, Bargmann!