The problem is that those experiments would invalidate only their assumption about the supposed structure of the supposed simulation, not the overall idea of the simulation. So the statement overall actually is non-falsifiable.
This is like saying "there are invisible elephants walking everywhere, let's try to see if they are made of neutrinos".
It seems like a silly argument. The physics of the outer universe are not bound by the rules of the inner universe. From the perspective of the inner universe, we can never hope to deduce facts about the outer universe based on out observations.
This is like saying "there are invisible elephants walking everywhere, let's try to see if they are made of neutrinos".