[syslog-ng] Unable to run several syslog-ng instances using file source driver file position persistence

Hello! I am using syslog-ng 2.0.8 (and tested 2.0.9 to see if it includes the feature...) and found out that there is still no cmdline option to define the path/name of the "syslog-ng.persist" file (like for the pid/conf file). So it is not possible to easy run several Instances of syslog-ng using the file source driver on the same machine and store the file positions beyond syslog-ng restarts ... e.g. in a cluster environment .... or did I miss a hidden config option? There was already a discussion about this some months ago. Is there a special reason, why this feature is not integrated in syslog-ng or is there only too less demand for such a feature? Regards, Andreas