These all seem like the same case. A room "mention" notifies the user. A message containing a mention notifies the user. An urgent message notifies the user.
Not exactly: on iOS for example, you can turn on something called "focus mode", which will mute/hide all notifications. Apps can break through focus mode for individual notifications if needed. For me, XEP-0224 is the exact right XEP to let the sender break through focus mode. Using it for mentions instead would mean I'd have to reinvent XEP-0224 for the focus mode usecase. I'd rather like a new XEP for the various types of mentions rather than having to reinvent XEP-0224 to be able to implement the focus mode usecase.
I'm not sure I think the second case is the thing to do, but it would work fine? Imho it is. TLDR; I'd like there to be a new XEP standardizing exactly this:
Another use-case is for the MUC service to use when a message contains a mention. When forwarding the stanza to a user that's been mentioned, it attaches the element.
-tmolitor