I just started to work with around 1000 releases to Picard. I went through all these recordings about a month ago and few of them are released the last year, still 30-40% of them where marked as changed in Picard. This forced me to do a very tediously work where I manually have to go through all these albums and verify the changes (sometimes I want to keep my local data so I have to open every release and check to prevent Picard from overwriting some of my own data).

I think that in the cases where the changed data/tag currently is empty, there should be an option in Picard to just update the file with the new data. This way I only have to manually look through tracks where there is a conflict between existing a new data.