I have a MP3-Album where the Artist is the Conductor.
The contributer_track Database is fine, as there are multiple entries possible.

The file has the following Tags:
TPE1 James Levine
TPE3 James Levine

This leads to Role 3 in the contributor_album Database for this Contributor and Album.
So the TPE1 is overwritten with the later TPE3.

In my opinion the TPE1 is far more important and should never overwritten.
So there should be a query to not overwrite the Role, if it's 1 or 5.
Or the simple and not reliable Solution is never overwriting.

The following Query in the Custom Browse Addon misses the the above Album, as the Role is not 1 or 5:

select albums.id,albums.title,substr(albums.titlesort,1,1) from albums,contributor_album,contributors
where
	albums.id=contributor_album.album and
	contributor_album.contributor=contributors.id and
	contributor_album.role in (1,5)