Will importing again duplicate my books or erase my reviews?
The app tries to reuse existing records and preserve what you have already written.
The import flow identifies existing records and handles recognized repeats to avoid duplicating books and notes. Existing reviews and ratings are preserved; imported information can fill fields that were empty.
Completed reads on different dates may represent rereads rather than duplicates. A book you have finished should also not move back to an earlier reading status just because a source has outdated information.