I believe I have found the answer: That the User Groups feature is not included in low end PepLink products, which the Surf SOHO certainly is. I base this on reading this: https://forum.peplink.com/archive/index.php/t-4183.html.
I admit disappointment, because this was the most interesting feature to me for selecting the Surf SOHO. I respect the reasoning, both the hardware performance and commercial reasons, but all the documentation I read before purchasing seemed to say some form of groups based QOS was available in the Surf SOHO. My point: Documentation could be made clearer that this feature is not in the Surf SOHO. Even so, the Surf SOHO is an amazing device for home use, making home-competition like Linksys and D-Link, etc. look like toys in comparison.