i'm talking stories with disparate pieces that you can't possibly figure out how they connect, until you get to the end of the story. so like, no possible chance of predicting what will happen, or anything like that. there's no way to get ahead of the author, BUT the payoff works. my question is simply: is this satisfying? does this work? i have a ton of different notes, thoughts/ideas, character sketches.... they all could easily be parts to their own stories, but i'm so interested in this one, collective world that i'm building, that i want to include every idea, everything i think of that i want to use for story fodder, into the same universe. is it a cop-out to do this? is it cheating to use as many of these pieces as i can, so that it doesn't add up until much later in the story?
I think it might work if every part in and of itself is engaging and has a storyline that's worth following. Otherwise the reader might DNF long before the end. And you also don't have to wait until the very end to tie the different story strands together. I would say at the beginning of Act 3 or somewhen during Act 3 would be a good place. If you can do it well, it will probably be super awesome. The challenge will be to hold the reader's attention for each of the sub-plots long enough that you even get to tying them together. P.S.: Oh, but be careful to not put in cliffhangers at the end of each sub-plot section. I have heard (and experienced myself) that when you're very engaged in one storyline with its characters and it then is interrupted and switches to another POV and storyline, it can be very annoying and might lead you to skipping the new part to know how the first one continues. Cliffhangers will exacerbate that feeling. So, better switch at points when there is a bit of rest and conclusion of a scene.
I'm sure you can execute this in a book, providing each plot line is split into chapters until the very end. Someone who executes it quite well in screenplay is Guy Richie (Lock, Stock and two smoking Barrels and Snatch). He has multiple storylines with characters often unaware they are influencing each other until the very end when they all collide in an epic, violent, and amusing end.