[Dovecot] Can Auth dict proxy protocol be used to validate a password?

I'm interested in using authentication via a UNIX socket as documented at http://wiki2.dovecot.org/AuthDatabase/Dict.

(We are currently using a checkpassword script to enable us to authenticate against a django app that stores passwords in pbkdf2 format, but I'm concerned about scalability as we grow - specifically the comment about performance on http://wiki2.dovecot.org/AuthDatabase/CheckPassword).

The example clearly shows retrieving a password, but is there some way to validate a password that was provided the way a checkpassword script does?

Otherwise, for performance reasons, perhaps we should implement a new password scheme directly for dovecot?

Thanks-

Tom