As far as I understand, support is complete and conforms to draft as of the time it was implemented. Since the draft expired, it has never been released. Moreover, I sent the author some comments about how the draft could be improved, IMHO, but received no answer (I don't recall whether the discussion was in ldapext or personal, though). If it can be useful, I surely favour its release, provided this complies with the project's policy towards support for expired drafts. p.