I would like that feature and think it’s worth opening a feature request for.
My use case: I have to send “bills” every month and for that I need to duplicate the old file, change the relevant information and send it. This saves me a lot of time compared to creating a completely new file.
Unfortunately, right now I have to copy the old file to a different folder, rename the file there and move the new, copied file back to the folder for all my bills. It’s an extra step and it works fine that way, but it is not the most intuitive and nicest way. So a duplicate with appended name
"<old-file-name> (copy <number>).<file-extension>" would be very nice.