I have not gotten a chance to

I have not gotten a chance to try the driver you have referenced.  I am embarassed to say I had thought I could only get the HDMI audio driver with the Radeon video card driver.  Never thought it could be installed separately.

I lost audio again yesterday.  I think I saw something for a split second that is a clue to the issue.  When I looked at the playback devices radeon HDMI audio was grayed out and on board digital audio was selected.  Then in an instant HDMI audio kicked back in without me doing anything.  HDMI audio is the default audio source.  It appears HDMI audio was momentarily disabled.  Then when I simply opened to look at the playback devices it enabled itself again.

Sort of strange.  Maybe the separate audio driver is the cure.