of course it would be feasible!
but: it would be -- mmm --- rather absurd to do so! :-)
if you collect for output a sla file you already a package that can be further edited by somebody on a different machine.
it would be easier -- and in my eyes also more meaningful -- to improve the .sla format and the way Scribus uses files to improve the way external resources are used by:
- allowing Scribus to pack them (and reference them in a relative way) in a project directory
- allowing Scribus to edit them even if they are zipped (in the same way as ODT is a zipped directory)
those goals are probably easier to achieve and would be very welcome from my side!
that been said, there are two big differences between LO Writer and Scribus:
- Writer reflows the content depending on various external resources (size of the page, fonts installed...) Scribus does not (so you don't need to a PDF to view the exact same result)
- Scribus often links to huge resource files (fonts, original images) and reduces their size when producing a PDF, the images linked from Writer are mostly of much smaller size.
personally, i'm not fond of abusing of PDF files to make them editable, but can understand why LO (or Indesign) is doing it.
i'm not really sure it's a good idea for Scribus, too...