

Oh, that’s interesting. Didn’t know about that.
I don’t think that there’s a way to list instances that a PieFed instance has defederated from, unlike Lemmy; while both have a list of instances at /instances, only Lemmy indicates which ones have been defederated from. It was a helpful tool to help me guess the sort of content an instance had.
Like:
https://lemmy.world/instances (under “Blocked Instances”)
https://piefed.world/instances
EDIT: It does show the last time that the instance sent data, and I guess you could sort of guess that if a large instance that probably has activity hasn’t sent data to the PieFed instance recently — like lemmygrad.ml and hexbear.net on piefed.world — then they’re probably defederated. But it doesn’t clearly indicate that this is the case, either.
They’ve apparently got an above-ground railroad, though.
https://en.wikipedia.org/wiki/NASA_Railroad