In reviewing https://issues.apache.org/jira/browse/UIMA-959, it says that JMS and Vinci can be used within an uima-as aggregate marked async="false", but fail if async="true".
The documentation has since been updated to say that vinci services cannot be used with uima-as because they don't preserve feature structure IDs, but SOAP does. However, the docs don't say that JMS and SOAP clients can't be used directly inside uima-as aggregates marked async="true". Is this still an issue? If so, I'll update the section 1.4.5 to say this. -Marshall
