Neil Gaiman himself, sort of. In his take on the Marvel Universe, the genius scientist character has figured out the world runs on storytelling logic instead of mechanical science and that he won't ever be able to permanently change his friend turned into a superhuman rock monster back into a human since "guy permanently turned into superhuman rock monster" makes a better story element than "guy who was a superhuman rock monster but is all better now".
For the current fic writers, I don't see it working. Rationalist fiction writers range from middling to terrible in skill compared to traditional fiction writers at the top of their game like Gaiman, and trying to do this would basically be trying to one-up Gaiman in his own game at his home field. Not to mention that his world-building is a lot more self-aware already than the perennial nerd culture favorite soft targets like Star Wars or Harry Potter, like the Marvel 1602 example shows, so you wouldn't have the nice obvious stuff to work with.
@First bit; that's Discworld-grade brilliant, but does the knowledge spread, as it does in Discworld where everyone is Genre Savvy, or is Reed Richards still Useless? Of course, the problem with narrativium is that attempting to take advantage of it is likely to bite you back, but is it better than not knowing?
My very first attempt at writing, waaay back in 2007, was a story about a guy who was thurst into a Narrativium-based world, which was kind of like an immense, live Let's Play for the entertainment a bunch of True Fae children (about three centuries...
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