Not sure if you could get the information from light flow, but if that were possible it would be more useful.
Notifications can be queried, if we could define regular expressions for app and notification contents then it could handle "other" non-standard types of notifications.
It would be great to have access to both unread and read counts. We could then build guages, lights, etc instead of the tiny default widget that is really hard to see. IMHO a smart watches primary function is notifications and the built in handling is pretty poor in Android Wear