Little bit old, but you may still have a need. Have you properly uploaded your key into the /License area so that it sees you latest purchase of your 100 site license?
Wil
https://talk.plesk.com/threads/great-idea-but-still-not-there-basic-suggestions.287797/
He said it all best in the above thread which was never answered. That said monitoring the forums and responding might be a good feature as well. Thanks for a great product.
Wil Hatfield