[Dovecot] Dovecot proxy in front of UWash?

[Vincent Fox]

Is it possible to use Dovecot frontends in front of UWash backends?

I need a proxy pool ASAP. There is not sufficient time to migrate the
backends for 40,000+ users so they have to stay UW for now.

I have been looking at Perdition but concerned about performance under
load. Dovecot looks really promising with it's non-forking mode. I need
simple dumb frontends no local mail.

Other questions:

1) Database?
Wiki only talks about SQL, can I have it map username to hostname using
LDAP or some other mechanism?
2) Kerberos?
I am hazy here, but can I have the frontends auth the user via Kerberbos
and things "just work"? Or do I need to stick with PLAIN authentication?
3) Port mappings?
Can I have the requests coming in on SSL ports remapped to non-SSL ports on
the backends? Thus the backends could have their load reduced somewhat.
e.g. client->proxy:993->backend:143