> It would be great to also get notified as discussion is happening in the various sites, without reading the spec, it's not clear to me if that's part of the standard.
Not really.
Not really.
1) a client-side event which informs the page of the annotation's publication URLs;
2) a server-side notification sent to the publisher's “well-known” contact address.
Either or both of these mechanisms may be used, each with its own use cases." https://www.w3.org/annotation/diagrams/annotation-architectu...
https://www.w3.org/TR/annotation-protocol/
https://www.w3.org/TR/annotation-model/
Any type of notification would be an extra feature performed by annotation software, but is not a part of the specification.
Your annotation client could query the annotation server at a known endpoint for new annotations. The results should be ordered and paginated, but the order and pagination used seem to be at the discretion of individual implementations.