most of expire is now ported from friendica, but the protocol bits to push out the delete notifications for the entire batch to all recipients of the original post are not complete and will take quite a bit more work. As a consequence, expire has been completely disabled until it is fully implmented since it could result in completely un-removable posts reminiscent of the infamous "Bonnie Nadri"  incident at Diaspora which we do not wish to re-live.