I’m not sure if it helps but maybe some of what you want to achieve would work by
- using the composition browser and tag all entries with some tag like “
identified composition” and then - apply the inverted “
identified composition” tag as an album browser focus.
My rationale: if a track is a performance of a known composition it will be catched by the “identified composition” tag in another browsers’ focus, too. So if the tag gets inverted, it’s working like an unlinked performance / unknown composition filter. Does this make sense / would it help your use case?
It’s static though - you’d have to update the tag manually every time you want to make use of it …
It would be even better if this could get used in the track browser but there it will fail because a tag assigned to compositions cannot be used as a focus in the track browser (I’ve hinted at something like this last December).