Remove fields under Extended Tags

I have fields that only show under Extended Tag - ican also see them using the softwate Mediainfo. I would like to remove all the tags.

Here the issue, if i select an album using extended tag, it will delete the field, but I wanto delete the field in all folders. Hpw best top go about doing that.

Large database so don't wanto load all at once.

I guess these were fields i create long time ago... lyricist, unsync lyrics... im think best to delete them insyead of odifying.

Any thoughts

You cannot edit fields in MP3Tag without loading them.
Why do you not want to load them all? You only need to do that once.

You can define an action of the type "Remove fields except" where you list the fields you want to keep.