I periodically run Picard against my music library to apply any metadata updates that may have been made. I’ve just updated Picard to 1.4.2, and Picard now thinks that there are a lot of differences, almost all of which are due to cover art. Upon checking to see the difference, I’ve found that the art Picard wishes to apply is usually of significantly lower quality than what I currently have - clearly in this case I don’t want it replaced.
Is there a way to get Picard to ignore lower quality art?
It is hard to define “higher quality”. A larger size (file size or image dimensions) does not necessarily mean a better quality, but it is the only way software like Picard could make a choice.
So indeed the best way to solve this is to upload the better cover art yourself.