https://bugs.openldap.org/show_bug.cgi?id=10268
--- Comment #3 from Ondřej Kuzník ondra@mistotebe.net --- You can always submit an overlay that tracks requests and enforces a rate-limit. That's probably better than adding functionality into slapd itself (and no dependency on cn=monitor, etc. would be needed).
Happy to guide you if you decide to go this route.