But wont you get that choice at export by chosing to overwrite or select to use unique names?
Maybe it also works better too to put the sequence first otherwise the sequence number will collide with the number of derivates you will create of a certain file. . It works fine for me. I think this rename function does its job fine even if its not as advanced as in Capture One. It is simple, quick and straight forward. I see nothing really to complain about. I uses it a lot and it has so far never caused me any problems