If everything in the universe has some consciousness, as I speculate in my post above, then you don't need to open the box to decide the cat's fate. Its already full of observers. The cat, the air in the box, the poison, flask and radio-isotopes, will all react "consciously" and will be affected by the cat. That is, they "observe" the cat's fate. An "observer" could be a thermometer, a camera, a microphone, or even just a lump of matter which experiences some change of state depending on whether the cat is alive or dead.

Responses to the same external stimulus can appear very differently to a generic observer. A gas will expand when heated; a liquid boil, a solid emit thermal IR. A plant will dry out, possibly die, an animal may just try to get out of there. A human might try to turn up the A/C or call for help. The Republican Party refuses to believe it at all. All are collections of matter responding to the same environmental change in different ways, depending on their capabilities and their "level" (or "type") of consciousness.

The multiple slit diffraction apparatus used in wave/particle duality experiments are deliberately designed to be as simple as possible, only binary responses are expected or allowed. In the real world, a spectrum of possibilities exist.

Yes, I agree that our investigations of quantum reality reveal behavior which is totally unthinkable in our ordinary world of "common
sense". But we just happen to be on the order of a meter in size and experience the world at about a second at a time. We are looking at only a very tiny piece of the universe, and have only evolved perception and behavior appropriate to that little piece.