Seriously, please boost. I think this will be a good thing. But I'm not sure.
I'm leaning towards making a rather basic caching proxy for public use. This will mean no IP/UA exposure to the instances but full exposure to the proxy operator (me, by default) on the pinky promise of not looking or god forbid indexing.
Still talking only about public/unlisted posts that some extension user saw on their instance.
Maybe it should be a proper fedi server itself so it can be suspended by those who hate it. Idk.