[Petra-Kathi]

Thanks a lot for the comments!

As there is only the "main computer" (running Linux) and one tablet (Android) involved in my case, the synchronization of different locations is not an issue for my setup.

The return path of annotations back to my "editing workplace" seems clear: export an annotated pdf back to the pc.

A question that remains: if I set "Let Mobile Sheets Manage My Files" to OFF and replace an older (annotated) pdf by a newer, same-named one (after cleaning up the hand-written annotations by another MuseScore session): What happens to the displayed version of the piece? Do I have to re-import it? Will the old handwritings be super-imposed to the new same-named pdf version? Or what else happens?

Kind regards,
Petra

[BRX]

No, you should be able to just replace the PDF and if name and the path in the database ares the same as before the new one will be displayed.

If there are changes in the pages or size of the images in the new source file there might be of course problems with the annotations kept in the database. I'm not sure, but I think I remember Mike mentioning 
some check if there are differences and discrepancies because of changes in the new source file. I think the annotations are superimposed on the new file though (but not 100 % sure, didn't try it).