You are correct that NS1 is not compatible with NS2, but NS2 is backward compatible. Similarly, NS3 can be used where NS2 and NS1 is required. This is how the aftermarket CVT fluid is compatible with all of them. Manufacturers cannot write anything in PDS by their own. Individuals or companies can sue them in the west.
I am not sure about Zic because they don't have any information on their website, but Kixx and Caltex do have PDS showing compatibility with different fluid types. I have seen people in the west using CVT fliuds from Castrol, Valvoline, Amsoil and they report very positive results. Some even report better than OEM fluid.
What's shift shock in a CVT? CVTs don't have any gears. Also, if there's any shock after fluid change, there are a lot of variables here like counterfeit fluid, improper fluid change, etc. You cannot solely blame aftermarket fluid.