Picard should offer the ability to copy and paste one or multiple tags with values between files. E.g. if you want to apply several tags already set on one file to another file you should be able to select the tags you want to copy in the metadata view, copy them and paste it to other files.

Currently Picard only allows copy and pasting values (plain text), but not entire tags.

See also https://github.com/metabrainz/picard-plugins/issues/313