In multiple export, I see that image is never included in exported image, and authors tag is messed up (usually the same for all tracks, even if source has separated authors for each track).
Audacity does not currently support Album Art in metadata. This limitation is listed in the release notes: Missing features - Audacity Support
- Album art and lyrics in imported metadata are lost when exporting. Workaround: Copy the lyrics (or search for them online) then add them back to the exported file in your favorite media player. Extract the album art using a tag editor such as IDTE (or use Windows Media Player or iTunes to search online for the art) then add the art back to the exported file using your media player.
Thanks for the answer.
Indeed, Audacity is an excellent tool, but such behaviour on TAGS should be improved. This is an option for which I would pay my part in a fund raising request.
Support for metadata varies considerably according to the file format and the software. Audacity provides fields for the 7 most commonly supported tags. For more comprehensive metadata support I would recommend using a specialist tag editor, such as MP3Tag (https://www.mp3tag.de/en/).