Climate Feedback group (see here and here) seems to be one of these Restricted Publisher Groups. However, it doesn't seem to be "scoped to a particular domain" (see for example here, here, or here).

Is this a third configuration of Publisher Groups? Or a different kind of groups altogether? Or have these domains been enabled one by one to the Publisher Group scope? Is this behaviour explained somewhere?

Funny how frequently this terms comes up, when talking about Genius. The difference between annotation platforms is significantly a matter of usage. Usage of Genius has a lot to do with snarky comments made by “the smart kid at the back of the class”. My perception of Hypothesis is that it’s much more oriented towards diversifying voices. But that has less to do with technical features of the platform than with the community adopting it.

Same experience, even in the Genius guidelines. The tool’s affordances (and name) revolve around snark. In the abstract, there’s nothing wrong with that. We need spaces for people to have fun, even if it’s at the expense of others. But the startup is based on a very specific idea of what constitutes useful commentary. That idea is closer to pedantry, snark, intellectual bullying, and animated gifs than on respectful exchange.