Google is not The Internet. If it is possible, please increase functionality for replacing or adding favicon to specified host address, or URL begin. It would be so usefull to cover common favicon by many favicons that depends on host, or host+url . Currently functionality is limited only to google.
well.. my argument is still valid that I want it to be as simple as possible. So Greasemonkey is your best option and doesn't limit you ;) As for the icon change part, you could take a script like this as your base: https://openuserjs.org/scripts/tfr/Better_YouTube_favicon