Copy keyword and notes data from a multicam clip to a compound clip?

Hi - I'm making a feature documentary and have spent many hours keywording and doing notes from ranges on multicams of each interview. I'd like to copy all the metadata onto another clip (could be a compound or optimised single clip) which has the same source file, but keep all the metadata / tagging etc. 
I've tried Merge (Postlabs extension) but it doesn't seem to do this. 

Any ideas?

Unfortunately there is no app for that

I'm writing as we speak to Postlab which includes the 'Merge' app to possibly extend it's functionality to this. Right now you can only merge metadata from identical clips/sync/multicams, but not transfer data from one type to another even if they have matching TC and contain the same master clips.