Asus has sent my ticket to HQ. I explained them that enabling "HDMI/SPDIF audio passthrough" in whatever app you are using to enable 5.1 sound over SPDIF doesn't cut it as not all applications support this passthrough and any processing of sound, eve...
If that's the case, then ASUS will no longer be worth my cash, nor will be it be considered a thrustworthy supplier in my professional life. This just needs to work.