I DO use Calculate Cover Size + MagicNodes to manage this "I need better artwork" thing:
- First I used Calculate Cover Size to fill Custom4 with artwork dimensions (like: 600x600, 300x301, etc...)
- Then I used Magic Nodes to create separated nodes for square and rectangular covers. See more details here
Now it's very easy to identify which covers I need to hunt a better version of.
- I use only one artwork per song, stored as a link to folder.jpg
- I like all my covers to be square, so I separated square and rectangular covers in different nodes.
The MagicNodes look like this: