That’s not the point. What you describe is polling notification. And yes Tryton is not able to do that with the current protocol without being insanely resource consuming. That’s why the res.request was removed in 3.0.
For such thing, tools already exist and we must not reinvent the wheels: Email and XMPP.
I’m not sure what you mean. This term is so often miss-used. But if you mean that notification will not be direct. This may be true with email but for XMPP is a protocol build for direct notification.
We don’t really care about demo database.
This is false. It is a huge effort to implement it correctly. So we must build on the existing.
But now, it is probably possible to re-use the new note object to have it linked to a generic/global object (or empty reference for global). This will not be direct because it will require a refresh from the user but it could be part of a startup dashboard.