Each sequential thing I've found / been informed of will be individually spoilered for convenience:

- In a dark Play Room area (near one of the many spawns) there's a red light in the back behind a bouncy foam pit.
- There's a very bright dot on a power panel beside the red light.
- Interacting with the dot turns the dot off.
I haven't found anything past that.

I'm excited to try and solve this myself, and will report back if I somehow find anything in this labyrinth. I have a pretty decent memory, but that's gonna be stress-tested HARD here.
I could search the map up and down, then activate the dot just to see if I notice anything, but this place is massive, so this'll take a while.