Just wrapped a shoot using the Epic and testing a Teradeck cube workflow. This was the first time we were making use of the hdsdi for both video and audio. We had audio coming in via the x A Box. All worked perfectly except there was no audio in the proxy files the teradeck recorded. After some back and forth, RED has confirmed that HDSDI audio is not supported yet.
Just posting as a PSA for those thinking about proxy workflows with the cube or other workflows that need HDSDI with embedded audio.