This is already possible via the Tag Sources dialog and one of the cover-only web sources. In the Tag Sources dialog you can right click on the cover-art window and enable Save image to disc. This setting is remembered across sessions.
The filename for cover art can be adjusted via Options > Tag Sources.
JJ Johnson, I think I do understand the term "aspect ratio" and what Mp3tag "correct aspect ratio" means and does.
You see that I am able to create pictures which can demonstrate how "correct aspect ratio" works in Mp3tag reality.
I am convinced that you are able to describe what you see, when you switch Mp3tag's "correct aspect ratio" on and off using the example pictures.
JJ Johnson, you can read, you can write, so try it out for yourself to find a textual description by describing what you see when you are doing it.
Begin with the smallest smiley example picture from my posting above.
How does the display change between the two states of "aspect ratio corrected" and "aspect ratio not corrected"?
Then try the red bar example picture, what do you see?