> It would seem that the mental jump of thinking of "Save" as "Save > Scribus File" > & > "Collect For Output" as "SAVE SCRIBUS PROJECT" is all that is required > to get what you want.
One important thing that seems to be a bit forgotten in this discussion is that Collect for output as far as I understand will also collect all fonts used in the document. And copying the same fonts back and forth seems like a bit of waste.
