Thanks for posting! There is actually a "Notify Editor" email option available to the author from the Editor Decision upload area (on the author's submission's Summary page), but it has to be sent manually, and it is easy to miss as an option. Making this an automatic notification has already been identified as a feature request (see http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=6791
, and please feel free to CC yourself to that report for future updates).
Unfortunately, we can't guarantee any sort of timeline as to when this will be added. Do you have any technical resources on hand who would be able to work on a solution? If so, we are more than happy to provide assistance in the way of help, tips, etc. If not, you may want to look at perhaps editing the template file from which that HTML page is generated, so that the Notify Editor option is highlighted/harder to ignore (and maybe placed *after* the upload field). If you'd like info on which template file to edit, just let us know.