With standard Mac configuration, you lose volume key control over the audio signal if you use optical or digital outputs. I currently use Soundflower to reroute the audio to get back volume control while using an optical cable. I'd be interested in trying your solution. PM me.
We created out own driver. As such you should still have volume control.
If you would like to test it please email me directly. Ymg7646@yahoo.com and I will add you to the list to receive the installation package tomorrow. Are you running 10.9.3?