It was just a handy feature when I was using a fence for a temporary project and didn't need the files when I was done, I like the idea of adding some sort of batch operations feature though!
I used Fences 2 for many years and recently started using 5 and 6 on my computers, and I realised that you can no longer delete files along with removing a fence, as shown here on an install of Fences 2 https://ibb.co/HDwRWVf6 I can't find any documentation about this feature so I'm sure why it was removed? But is it something that could be added again as it is an occasionally handy option when organising my desktop!