[syslog-ng] help with milti-line-mode 3.5.4.1

I am having two problems with the multi-line-mode (I am using a pipe source for testing). 1. The last message written to the pipe will not be processed until the start (multi-line-prefix matches) of the next message is received. This makes messages delay until the next message arrives. 2. The last message the is written to the pipe is lost if syslog-ng is reloaded or restarted. Is there an option for how long to wait for the "full" message to arrive? Is there an option to specify what the "LAST" line of the mutli-line message should match? That way the message is known to be completed. Thanks for your time. Evan.