If you think the answer to this will be a distracting tangent to this thread, quote this note and reply there.

What are the concerns you worry may cause a user to shy away from attesting with themselves as the reference user, UX-wise?

Is it about others finding out what you think? In my ideations on the subjective social graph, I've always preferred solutions that are optionally private. So when you're (algorithmically) assessing your conceptions of influence, relevance, etc. the conclusions are private to you, based on your private attestations + whatever else you know about the (transitive) public attestations of others.

And you can opt to surface certain of your own attestations as Public; which would in turn influence the conclusions that peers (who trust you by degrees) make when they are assessing their worldview in domains that involve you. But your private data wouldn't be visible to them nor enter their worldview.

(Incidentally, this set of affordances also leads to the feature of "masks" or personas/aliases. You could instantiate a new blank slate mask and build it up to be "a person who believes X set of things", and then view the world through those eyes. A distinction between public/private + multiple "mask" instances would allow this (let's be honest, probably social apocalypse-avoiding) exciting feature).

Now that I've thought aloud about that here, I see what concerns you, UX-wise. There are a dozen net-new concepts there to introduce slowly to a new user. With great power comes... great new user onboarding flows that level them up slowly 😆