This is problematic for a number of reasons, most of all is that this rating that it generates is NOT transparent to the user. This page is used on PieFeds main page when you go to register, it’s part of the instance picker. The defederation rating under More is where this shows up. For instance, this means that instances like anarchist.nexus have a “OK” rating but instances like multiverse.soulism.net have a “GOOD” rating.

https://piefed.social/auth/instance_chooser

The only measurements here seem to be stability.

"These servers are ordered by speed so it may vary depending on time of day, etc"