I use Everything every day, excellent work.
One thing that I frequently use is to put some files into Dropbox for transfer to other devices. Unfortunately, it is hard to remember if any of these files are also somewhere else, so I need to find which file names are unique and avoid removing them after transfer.
I do it one after another but a function that will show in duplicates in subcatalog that can then be safely removed would be a great addition to Everything.
Wlodzislaw