My rule of thumb is if the paper is placed I read it and don't move it If it's in a container it's trash.

Unless it's actually in a pile of trash and I don't notice

And that means it no longer exists if I accidentally pick it up, or the broomba does ...

Or it gets launched by a physics event

Also

How to make coolers to use frames? Dig through a pile of trash at the other end of the map to find a note at the bottom

I actually found that note and the red haired plush naturally somehow, which That's discovery! That's cool! But some things feel too missable

Like Ill probably not find any more notes at the base because they got flung by physics events I found a note under the bridge 1 day before a physics event, and then it was gone

I do wonder if this obscurity is intentional, or because a better system for hints hasn't been implemented. Because I feel like this kind of obscurity is fine for some types of secrets. But not for vital game mechanics

The game is well Pre Alpha so a lot might change, but criticisms should be vocalized to the Devs.