Ok you are right but there is another problem with your idea: now there are 4 application from Piriform and if you introduce a dedicated Dup file checker there will be 5 separate application. the problem is that these applications are not all-in-one; my suggestion is introducing a comprehensive application containing: CCleaner, Defraggler, Recuva, Speccy, and Dup file checker; in fact this application will be a tune-up utility.
Regards