Improved or pre-Improved? The above is a pre-Improved and if you were to add the additional rider-weight it will be happy enough with the Zu. If it is a S2 Improved you have next to no chance as it was never designed to balance out that sort of weight. The obvious visual difference is the counterweight assembly, the Improved is far shorter.
This is an Improved, its a fixed shell, but the counterweight assembly looks the same. These arms are designed for and give their best with MM carts. It can’t balance out a heavy cart without modification or finding a truly rare as hens teeth heavy SME counterweight.