Earlier quoted context omitted.
Hint: You can sync the library for free by making an account. You need the "Zotero Storage" only if you want to sync the files as well. However, you can simply sync the folder ~/Zotero/storage using SyncThing. You could also use WebDAV, but SyncThing is just so much easier (set up & forget). The IDs/Metadata is consistent among syncs. :) Of course, that doesn't resolve the privacy concerns, but personally idc about t…
This is completely missing the point of GP. You can't (unless something has changed) sync metadata without using their servers. webdav is for the data, not the metadata. If you don't personally care about privacy, fine, but that's irrelevant here. Replicating the local Zotero folder across devices won't properly sync the metadata in the face of concurrent changes. If I didn't care about privacy and freedom I would ha…
You are entirely free to use one of the many proprietary products...