A few times a year, I clear out my library (tracks and crates) and rebuild with pre-organized M3U's. New tracks are added, many of the previous tracks are re-added and a few are intentionally removed. I notice that when I CTRL+Del the tracks and crates from with Serato, and then re-add the M3U (via drag and drop), the track info (mostly track length) from the previously stored files is not there. I rescan ID3 tags, but nothing repopulates until I manually re-analyze the tracks, which can be a time-lengthy process, especially where 80-90% of the library has been analyzed at one point or another.

I understand that the databaseV2 file stores the analysis status of the library, so why is the track info disappearing when I delete just the tracks? Is there another/better way to go about this?