Re: Paying for Document
Of course it isn't required. but the government leeps many lists for many purposes. Why were ham radio operators required to learn Morse Code? Not for international purposes, but in order to ensure the Army had a pool of trained radio operators. I knew someone on the local selective service committee, who assured me they had access to all sorts of lists, in case a draft was called and they needed special skills.
Bear in mind the fed also stockpiles what are considered "strategic metals" in case imports are cut off. Providing for contingencies is something civilians scoff at. But then again, we have the Interstate And Defense Highway System because a young army officer named Dwight Eisenhower got disgusted with trying to run convoys over bad roads with lousy signage.
All very similar to what NOAA refers to as "the prudent mariner". There are folks who just have to make other plans. Would they mandate registration? Probably not. Would they quietly say "Hey, we use that, don't throw it out." Sure.