Auto generation of channels fails when adding <context:mbean-export/> to config (when there is no <int-jmx:mbean-export/>. Appears to be because the mbean exporter causes beans (endpoints) to be instantiated before the channel initializer has run.
Work-around is to add...
...before the <context:mbean-export/>
Failed with <control-bus/> and <service-activator/> with undefined input-channels.