jBPM Script task multiple incoming connections issue. Runtime has no support, but web designer

The jBPM5.3 web designer has support for Script Task to have multiple incoming connections and generating valid BPMN2 file. But when the process is deployed and it is throwing the following error while it is loading the process into knowledge base.

Caused by: java.lang.RuntimeException: ProcessLoadError: unable to parse xml : Exception class java.lang.IllegalArgumentException : This type of node cannot have more than one incoming connection!

I have tried setting the system property -Djbpm.enable.multi.con=true as it was mentioned in one of the posts, but am still getting the same error.

I have taken look at jira( https://issues.jboss.org/browse/JBPM-3372 ) and it is mentioned "multiple incoming connections support has been added to run time engine", but I still don't see this support yet.