I think a bigger worry for writing a log file to a flash filesystem
would be, well, writing the log file to a flash filesystem. Even
a million-cycle flash card can wear out fairly quickly if syslog is
operating on it, no matter what the format. It would probably be better
to write a custom logger rather then use syslog, or syslog to RAM and
have a cron job copy it out to flash in a cycle-controllable way (like
once an hour).
-Matt