Art, you're trying to force a point where there is none to be made.
1) "then you're screwed if you change your mind". The point is that you don't change your mind. Once you realize what you want, that's is what you go for. The expeience of it is so strong that you simply don't change your mind. Peopel who post-visualize in the DR, those are the ones who constantly change their minds.
2) "What happens if the paper you're using suddenly disappears?" Well, obviously, you use a different paper. The characteristics of top-end FB papers aren't so drastically different that a negative is suddenly useless if that paper disappears. When graded Brilliant went away, I switched over to Seagull with no problem, still print the same negs on Seagull as I did on Brilliant. Some sligt re-calibration is necessart to determine the range of the new paper, but you won't find it much different than the other top-end brand.
You've got no point here and you're arguing up a blind alley. You don't have any experience inthis type of photography so I'd suggest you stop trying to invent reasons why it can't work when the best photographers of all time have made it work for decades and decades.
-Mike