If there is absolutely no point what so ever in 192Khz, I struggle to think why it has been invented. I accept your point re how high the human ear can hear but perhaps with 192Khz there will be more detail? I dont know, as said im not that techy.
There has got to be some use for it in pro audio. more detail perhaps?
Have a look at sampling theory. You can hear 20Hz - 20kHz. Nyquist says to replicate that accurately you need to sample double the highest frequency involved, hence the 44.1 kHz standard. Sample rates above this are to accuracy represent frequencies above this, which as you can see from my post above is unnecessary as 44.1kHz would be perfectly acceptable.
Infact, you are doing the worst thing you can for quality. You have a 4 grand set-up and want to use a free driver or a cheap soundcard to hit a number on the output which as you say yourself, you don't understand the technical side but just assume it is better. I didn't look at the DAC closely, but is that not a soundcard. So really what you need is the correct driver for this device?