syslog-ng and logging with milliseconds

Hi,

Although I know how to do it directly in the syslog-ng.conf file I can't find a proper method to use to configure the BigIP. As far as I can tell there are no parameter that can be used to add the frac_digits(3) to syslog-ngs options{}.

These are the parameters that can be used to modify/edit syslog-ng through tmsh:

modify syslog
  options:
    auth-priv-from
    auth-priv-to
    cron-from
    cron-to
    daemon-from
    daemon-to
    description
    include
    iso-date
    console-log
    kern-from
    kern-to
    local6-from
    local6-to
    mail-from
    mail-to
    messages-from
    messages-to
    remote-servers
    user-log-from
    user-log-to
edit syslog
  options:
    all-properties
    non-default-properties

tmsh modify /sys syslog include "" will only append the string to the config file and can't be used to modify existing options.

The linked solution (130080) only details how to log to a remote syslog.