It is currently difficult to add performer tags to the preserve tags list. Usually performer tags have a role assigned, such as performer:vocals or performer:guitar. In order to preserve those one needs to add all variations.

It would be better to either have "performer" preserve all those tags or allow an explicit syntax of "performer:*". The same is true for all other tags with a colon-notation.

See discussion at https://community.metabrainz.org/t/unable-to-preserve-performer-tag/482851