Does This Count as Macroscopic?
Quantum entanglement has been found in objects big enough to see. Despite that, I don't think they count as macroscopic. 1016 carbon atoms is less than a Planck mass. Above a Planck mass, gravitational effects are greater than quantum effects. I think that means it's possible to tell where something is by its gravitational field. In other words, above a Planck mass, all objects are observed whether or not somebody is looking.