I noticed this feature and I find it surprisingly useful. So I enabled the checkbox on auto-import.
2 issues.
1. 11,000+ songs on my library and it seems it never actually finishes looking them up. Next time I hit auto-import it tries again.
2. In the same album, some songs it finds and fills ok and others don't. Coincidence or not, songs with the name only work fine and songs with "Song Name (featuring Joe Smith)" it does not find on the same album. So album matching could improve this.
