Maybe now is the time to switch to @zotero? The things missing from @mendeley_com Reference Manager can be handled with Zotero plugins afaik.
Is the time to think about the moving, at least. Zotero 6.0 (beta) has good reviews
6.0 just came out of beta! zotero.org/blog/zotero-6/ I jumped into the deep end, and _switched_. @zotero 6.0 has a PDF reader, which was the main thing holding me back. Renaming, bibtex sync, deduplication all works out of the gate or with plugins. Only thing missing: watch folder