[oren64]

This is only a request, and if you have the time to do it, I don't know if it's even possible.

To take the book status (Read, Unread, Finished), from sqlite file (I didn't find where it's in sqlite file), and to load it, into a custom column.
So if you finished a book on your device, when you connect the device to calibre, it will change to Finished in the custom column.
I don't know how it will work if somebody have more than one device.