Has anyone implemented/devised a pattern to implement a structured exception handling framework that works in the context of designer 2.0?

Of course it's possible to trap an exception event raised by a class like this:

Ext.util.Observable.observe(Ext.data.Connection);Ext.data.Connection.on('requestexception', function(dataconn, response, options)
or this:

Ext.util.Observable.observe(Ext.data.proxy.Server);Ext.data.proxy.Server.on('exception', function(proxy, response, operation)
  var msg = Ext.String.format("{0} error reading {1}", proxy.$className, proxy.url);
  var title = 'Proxy exception';
  console.log(Ext.String.format('{0}: {1}', title, msg));
  this.reportError(title, msg);
But there's a lot of classes to watch this way, most with different exception event signatures and what about those which are less prudent about catching and reporting exceptions?