Keep track of "not found" ISBNs with timestamp in the app

Using the app's scan mode puts up a "not found" message that often includes the detected but unfound ISBN number. Would it be possible to save this number — perhaps kept in a separate list than "added books", but time-stamped in the same sequence as the found books? The same could be done for apparently-valid ISBN numbers that may be "not found" because they are from a different country or source.

That way, a user could review this unfound list to do a more refined search later: the ISBN would be the placeholder for the unfound book, and since it would typically be physically located between found books added in a batch, more readily accessed to get at the essential details (and to get a cover image).

To add even more value, when an ISBN is not found, you could offer the user the option to take a photograph of the cover but still keep it as a separate entity to "added books" that could be reviewed & edited later.

(I encountered this as I was processing books on a shelf: I'll need to go back to capture details for some older or foreign books amongst the many with bar codes — but it would be a much easier task if I could review the unfound ones in the context of the found ones.)

++ agreed

And it would be useful to be able to DELETE an "unfound ISBN" notice in the app.
Most of those are in fact bad or partial scans in my experience.