One of my editors found a clever workaround for this one. Since only those review files uploaded by those in the Reviewer roles are easily selected when sending notifications to authors, the journal created a faux reviewer called Faux Reviewer and uploaded the decision letter on journal letterhead as the Review file from that “reviewer.” That way, the file can be easily attached to the standard email notification to the author.
We’re still looking forward to the feature being included in OJS, but we at least have something workable until that happens.