So, just a waste of time for anyone hoping to see an exploit based on favicons.
Favicons are very useful for spotting phishing sites and finding forgotten servers.
OSINT is about exploiting public data for private benefit.
The article was meh, others are expressing similar opinions if you read. It is OK that you find it useful but for me was sincerely expecting something more from the title.
So, just a waste of time for anyone hoping to see an exploit based on favicons.