[Dovecot] director with same director / backend servers

[Will Yardley]

I know this has been covered somewhat, but I'm still not totally clear.
I'm trying to setup a 3 node cluster with 3 directors and 3 backend
systems.

This post (from 2012) suggests that proxy_maybe should work with director:
http://www.dovecot.org/list/dovecot/2012-December/069806.html

However, these two posts (from 2013) seem to say that it will not:
http://dovecot.org/pipermail/dovecot/2013-November/093776.html
http://dovecot.org/pipermail/dovecot/2013-November/093809.html

When I try to just set =proxy_maybe=y in my LDAP config's pass_attrs,
and not have an explicit 'director' listener for pop3-login /
imap-login, it complains about lack of a host.

May 22 14:28:08 XXXX dovecot: pop3-login: Error: proxy: host not given: user=<XXXXXXX>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1,
secured

Guessing the answer is "no", but is there any way (with v 2.x) to have
one regular "listener" for imap / pop3, and one "director" listener for
each as well, using the same instance of Dovecot? Has anyone gotten this
to work successfully?

I'm using LDAP, and do not want to explicitly specify a host for each
username, I just want director to balance users across the 3 hosts.

Obviously, I can just create two instances, but not only does this make
the config more convoluted (especially following the convention of
having the config files broken out into a bunch of files), but means I
have to modify the default init script to really do it cleanly
(something we were doing on the older iteration of this system that I
had really been hoping to avoid).

I'm assuming it's not possible to simply have the listeners for
'foo-login' execute something different depending on the port? I tried a
couple different ways of configuring this, but it didn't seem to work.

Dovecot is version 2.0.9 from RHEL 6.

w