Feature: Selectable fields when adjusting tags

Hello, I recently started using MP3Tag and it is a great program. I have one request. Would it be possible to add selection check boxes to the various fields when using the tag download feature. Often, I fill in tag information manually for albums, especially artist name (Beatles, The vs The Beatles). Or, I only want cover art and not the rest of the tag info. Or I might have scanned a copy of an out-of-print cover and not want it overwritten with re-issue artwork. It seems that if you use the tag download feature, you MUST overwrite all the other tag info you already have. Being able to enable or disable overwriting of each tag field would be a big help. Sorry if this is a duplicate feature request or if I am missing some obvious way of overriding the default behavior. Thanks!