Have an option for automatic backup to only be for new photos

Currently, if I set up automatic backup, it will try to backup all the photos that are already in that folder. It would be nice to have an option to disable this behaviour and have automatic backup only apply to new pictures to avoid duplicates and unnecessary bandwidth usage.

As a sidenote, the option to not show folders with .nomedia files (folders that have been marked to be ignored by media apps) would also be nice.