Perhaps UA is being too generous with their NSRA policy and should only extend the perk to immediate family members. While a bit rigid, I suspect it would make it a heck of a lot easier for UA to check against.
Also be curious to see how often sticky fingers happens between the GA and pax who are friends of the agent (i.e. non-elite pax bought revenue Y ticket and magically the computer says their CPU cleared!). That being said, I don't suspect these "upgrades" occur too frequently, especially given the high demand for upgrades (i.e. CPU lists which are multiple pages long). You know you are not getting that upgrade when a line forms for GS members!
-James
Not sure if it's 'cheating' but I often see FAs giving premium class food and drinks to non-revs in Y or other goodies like amenity kits/blankets.
Not cheating, it's called not following officially stated policy. As someone who flies UA fairly often, that is one of the couple redeeming qualities of the airline: the ability for agents and crew to throw the book out the window to deal with the realities at hand be it IRROPs or serving a snack several hours earlier whilst seated in Y on one of those long haul TPAC segments.
Safe Travels,
James