I recently observed that we cannot propagate ECID (Execution Context ID) from one composite to another if their interaction is through an adapter - AQ, DB etc.
Though it works for JMS Adapter!!
Oracle officially claims that ECID propagation is not supported in Technology Adapters, as the adapters don't support headers.
So it works in JMS case, as the ECID could be passed through JMS Header Properties.
In AQ case, it doesn't. I think the 'USER_PROP' section of AQ could have been used for the same.
I was even thinking if I could set the ECID myself manually in a composite, then I can arrange the passing of ECID somehow in my message.
But not sure if even that is possible.