Can there be an option to see unsynced items on the desktop folders as placeholder items (perhaps using a placeholder icon like a world instead of a check mark?). Probably similar to oDrive and Bittorrent Filesystem’s on-demand read and download.
So further borrowing from BTFS, perhaps placeholder files could be pressed and then the link would download as needed. Placeholder files would also act like real files.
Say I have an old template folder somewhere. I did not sync it offline, so I copy-paste its placeholder contents into my new template folder which is synced. Then these files remain unsynced, but on my Google Drive cloud, the files have moved to the new folder. If I want to sync them, I’ll use selective sync normally or batch select the placeholders and right-click sync.
The possibilities are endless.