WHY - Can I Edit Author or Name in the audiobooks I have added to iBooks on MacOS (12.1)

I currently have over 2,000 audiobook titles in my iBooks library and as a result I have had to organise them by Author, Book Series and Title. This is easy to do with the source files - by editing the file name AND all associated entries (tags or fields) using Tag Editor.

I have had to accept the fact that UNLIKE iTunes or Music one cannot make such edits within the iBooks app. So I copy the source file, make the edits to this version; then delete the title I wish to change from iBooks, restart the App, and add the new version of the file with new File Name, Author, Book Series and/or Title saved into the file. More often than not the Title appears back in iBooks with precisely the same Title and Author as were shown in the version I deleted. AND this is just nuts.

I hesitate to try to edit the Books.plist, which I believe is the Library Database, without knowing precisely how to do this.

Does anyone know how to change the performance of iBooks or to Edit Library entries for title or author?