Yes but I don't understand how this can be seen as modelling anything but the experiment one is performing: the way I interpret this proof of quantum supremacy is (and again I know this is incorrect but don't know why) almost like selecting any physical phenomena to which a simulation of it is computationally hard, and then say that the result of this experiment is the returned value of a "computation". I feel it's almost like claiming you are going to simulate fluid dynamics with an actual water tank, some dye, and a camera.