Holy crap it was right under my nose and better than I imagined.
[Link: crestron.com]This little baby will allow me to send all sources to all zones regardless of the capability of the zone in terms of audio.
I can now send all my audio sources to each hdmi zone regardless of the capability of the zone. For example if the zone employs an AV receiver then these zones will get a very high quality audio experience. If the zone is just a TV with built in TV speakers I'll still be able to send an audio only signal to that zone. Granted I only have 6 inputs on the lower cost DM switchers but at least I can now do what I want.