Dear a.l.e.,
thanks a lot for your fast answer, and even more for its content. I didn't expect such a positive reply

I have no idea of programing, that's why I can't even imagine the difficulties of that idea. But, nevertheless, I created the following design with Inkscape, how it could be the tool we are talking about:

List of minimal features:
-Open Master Documents
-Export Master Documents, which means: Scribus can merge and export several single documents as one PDF,
without opening every single document (for a large book, we would save an amazing amount of resources). It would be extremly powerfull, if we can export a 300 pages book, for example, without opening all the documents/chapters. If Scribus doesn't need to open the documents for exporting them, but just export the Master Document.
-Synchronize the numbering of all documents within a Master Document
-And here, I guess, a difficult one: creating an index of contents using all the documents within a Master Document.
Of course, it could be always improved and improved, implementing more advanced features, but if Scribus would do the things described above... Well, it would be an amazing jump of quality for Scribus, from my point of view.
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