as an engineering student, ANSI standards are extremely reliable; since a single jack is designed to a safety factor of 1.5, those things could probably support 8000 pounds (safety factor 2) without even getting close to the young's modulus.
in other words, you could probably sit the entire Z on a single stand and that stand won't budge, much less using two or four stands and splitting the Z's 3300 pound weight across those stands. the fact there's an opening doesn't affect the strength of the design much. would probably be able to safely support 6000 pounds if it were completely enclosed. "regular" jackstands are full of holes too! do you not trust those?
I would consider shelling out a good amount of money for the hub-stands; I see them at race garages. to be clearer, it would be those jackstands that mount on the hub, sort of like the dynapack hub dynos:
