A nice feature for the SFV module would be to enhance the preupload hook handler so that it can block people from reuploading a file that is already uploaded and confirmed via SFV to be correct. If a user tries to reupload the existing .sfv file, they should be blocked from doing so (this forces the user to have to delete the .sfv first before reuploading it).
Additionally, the SFV module should probably prevent more than 1 SFV file from existing in a directory at any given time (or automatically rename it from .sfv to .sfv.duplicate or something along those lines).
