That’s right, but it doesn’t specify what exactly is disturbance/measurement. We know from observation that interaction with a macroscopic system causes wave fu

That’s right, but it doesn’t specify what exactly is disturbance/measurement. We know from observation that interaction with a macroscopic system causes wave function collapse seemingly instantly. But we don’t know much about in-between behavior, like what happens when interacting with another microscopic system and does wave function of a microscopic quantum system collapse on it’s own given enough time.