The UPS guy is saying what UPS should say. Of course, the reality is that UPS has no idea what's inside of all those boxes.
I've had lots of non serial numbered/non ffl parts shipped to me via usps, FedEx, and ups.
This guy is completely full of crap.
While I see your point, I can still believe that UPS is erring on the side of caution while they try to figure out all the legislation involved in being a courier for this type of thing.
But not a machine that can cut the fire control pockets for me?