Hi,
yes, I would say that you need to stick to what is documented in dev guide.
Unfortunately work has slowed down if it comes to new development and especially BPMN2 support. At the moment we are trying to focus on bug fixing to be able to release 4.4 of jBPM.
To trace progress, regardless of the type of changes, please take a look at jira (jira.jboss.org).