The importer actually does something like that already! If you’re curious about exactly what’s going on, the key parameter is SINGLE_ARTIST_THRESH:
The way this works is that an album is considered “single-artist” if at least 25% of the tracks share the same, primary artist:
You can see that this triggers the comp flag and uses the name “Various Artists.” You might try doing some debugging around that to see why it’s not being triggered for the album you mentioned.