I'll admit I'm not super familiar with Ito's work (just the really popular stuff). But I thought Matt brought up an interesting point
Like you mentioned in the Uzamaki film there was a snake cult because afaik there's no explanation in the Uzamaki comic and I'm guessing they needed a more conventional kind of story to build a motion picture around.
Trying to put something completely unconventional into a conventional format doesn't really work most of the time. What if you just decided to break all of the rules of RPG story telling to create something truly bizarre? The structure itself would mirror the subject matter.
Of course, I don't really know how
fun that would be but ¯\_(ツ)_/¯ just spitballing here