Your comments

YES, i've seen it.

But it requires the host to actively post a note to the guest.

I've been looking for the automatic notification.

No - i don't want to delete guest.

I just want message/notification to be displayed to the guest when HOST disconnects without ending (deleting) the session.

Hey, thanks for suggestion, however it's not the same thing - the end-of-session you're talking about is when the sessions is ended i.e. terminated/deleted from the system.

I'm talking about situation that support session still exists and support agent have disconnected.