I'm sure the issue is not being ignored because it's deemed unimportant. It is important, and probably too complex to be dealt with easily. It's also the sort of thing where no one solution will be optimal for all situations and make everyone happy.
Having a more or less established collection, I don't find this to be a huge problem. Nevertheless, I do find it frustrating when the behaviour is confusing, or simply won't do what I need it to do. One thing I would dearly love it to do is add trailers to [File Path]. That requires the new file literally be added to the field, not changing the value already recorded or adding a new movie record. Should this be handled within the current design, or should there be other means of detecting and adding trailers? [Hint: There will be no agreement on how that should work.]
This issue can't be separated from that of duplicate recognition and handling, which has always been problematic. Many don't seem to appreciate that for every movie in their database, there might be 100 invisible ones included in filmographies, awards, etc. When a movie is added, it's necessary to determine (or at least try) to find the invisible record that very likely already exists.
If and when nostra has time to address these things, I would suggest the scan results dialog needs to be very clear about whatever it's able to do with a high degree of assurance. For things that are ambiguous, it's okay to allow the user to make changes (as it currently does), but it would be much more effective to provide some interactive tools. In the time I spend wondering what it will do when I make some change, I could select an existing movie from a list (or "add new movie") and tell it exactly what to do (i.e., change existing path or add new one). Because the window is modal, it would also be helpful if there were a "bookmark for follow-up" option for those situations that will remain ambiguous until the user can examine the results. It's often easier to guess and then correct the results.