Sorry you had to switch over. As I mentioned over email, I used your same library and could not reproduce any issues whatsoever while synchronizing to OneDrive. It's very difficult to fix an issue that you can't reproduce. I haven't had time to add extensive logging for the library synchronization feature, but I think this will be necessary to investigate issues like this. If the problem is still just due to the connection being interrupted, then there is no solution other than having a mechanism in place to forcefully restart the sync but resume at the point that it failed (which sounds a lot easier than it is due the asynchronous nature of everything).
Mike
Mike