I need either simultaneous audio output on the full HDMI output and the Toslink output, or discrete remote codes to select the audio output.

Since the documentation indicates the Edge will only output audio on a single output at a time (why I don't know) I suspect my only hope is that discrete codes for selecting the audio output is available.

I'm sure there's a reason for it, but I don't understand why you have to select an audio output in the first place. Seems to me that the Edge shouldn't touch the audio on HDMI other than to inject digital delays if necessary and should also pass the audio on Toslink if it's a compatible format/bitrate.