slight problem with qmqpfront-qmail and cvm

I've been trying to get cvm-vmlookup to work with qmqpfront-qmail but
have been getting nowhere.

Situation:  I've implemented a system to filter mail before delivery to
my mail server (running vmailmgr.)  Previously (and currently) I'm
running smtpfront-qmail on the mail server to immediately reject
messages to invalid recipients.  Now, the new setup is mx1.mydomain.com
accepts incoming smtp and relays to mail.mydomain.com via
qmqpfront-qmail

This configuration works like a champ, but I have only one complaint.
qmqpfront-qmail doesn't seem to utilize cvm-vmlookup!

I tried to use smtpfront-qmail to accept the messages on mx1 and verify
recipients using cvm-udp, but the connection is troublesome (50%-ish of
the time it accurately determines valid/invalid recipient, the other
50%-ish of the time it returns an unknown and 451 temporary error to the
sender, not stable enough)

So, I figured that I'd do the next best thing.  Reject messages during
qmqp delivery using cvm-vmlookup, but it seems that qmqpfront doesn't
even attempt a lookup.

Are the CVM features not present in qmqpfront-qmail?  The documentation
for qmqpfront-qmail is very scarce.

Thank you for any help you can offer.

Michael