Although this help provide some rules of thumb it made me a little nervous. In our app we have a lot of power in our routes’ actions. And often when actions are propagated (bubbled) like you describe it gets really confusing where things went wrong. Who captured the action? Who sent it? Who bubbled it? Who resent it? It get so confusing.
Finally the worse situation is when I need to change an action’s behavior. I have to remember every possible use case all the way down. These actions become monsters to handle every possible component under it might attempt to use it.
I think the point is that with DDAU it is trying to help make sense of this mess. By explicitly passing action closures to your components they only have to worry about on level up. This named chain of properties makes debugging easier. Shows were things are happening. And it allow changes to happen in the right places.
I would highly advocate that DDAU be implemented with action closures before relying on controller or route actions.