syncrepl with mirrormode compatible with OpenLDAP version 2.3.43?

I have setup my slapd.conf file with the directives for syncrepl with mirrormode on. This seems to cause issues with any write operations that occur after setup. (syncrepl does work with the provider/consumer setup but so far not with mirrormode) I am now guessing that mirrormode is in fact NOT available in version prior to 2.4 I have searched for an answer, but have yet to find any clear statement saying that it is not supported.

thanks in advance to anyone who can confirm or deny that syncrepl with * mirrormode* is or is not supported in version 2.3.43

-h