I seriously doubt anyone is going to take a shotgun apart to count how many parts are stamped "US". From everything I've seen, no one can cite one single case of someone being prosecuted for a 922r violation. Most think it's probably just another charge that would be tacked on if you ever get caught doing something much worse (like running red light charge after being charged for fleeing police).
With that being said, for me, it's not about what the odds are of being caught. I wanted the titanium full length tube (which came with the follower) anyway. What's a few more bucks after that and the cost of the shotgun in order to be completely legal? Plus, I'm into the NFA stuff and I'm not about to let something silly be a snag for me after I dot my I's and cross my T's on everything else.
But hey, make your own call. Maybe the cost of compliance justifies the negligible risk. And if you ever get caught, you can always say you were "the first"!