John,
Your idea of just setting the ksession when creating the handler is indeed what we recommend (and also do ourselves in some handlers). Note that this ksession is the same session as the one that creates the process instance, but the object that you retrieve (when using persistence) is actually a wrapper around the internal session. That should however just delegate to the internal session.
Did you have any issues when setting the ksession like this, and if so, could you provide some more detail?
Thx,
Kris