Having just updated our app to use T5.1.0.4, I checked out the changes made for TAP5-624 to support javascript callbacks on a zone update. I'm a bit surprised at the solution for this which is to fire a client side event. I thought that it would have used the JSON object returned for partial page renders which already has a script: element, allowing addScript() or something similar to be used.
Is there a reason that this isn't possible or isn't a good idea? It seemed an obvious thing to me since the facility is already there but just needs exposing to users.