the reason I do ask that question: there are PR1 Projects (without index-page) on Wikisource projects. All these projects do use seperate files. There are also people at de.wikisource who want to use PR1 and PR1 only, as they did for years now.
for example:
(to name the biggest)
there is also an understanding in that community not to transform these PR1s to PR2s.
If the task is to link Wikidata with Commons and Wikisource and use the same sources, you shall link the given category (given in a template on wikisource-project or wikisource-work-page - that is Vorlage:Textdaten in
de.ws)
-- Anika