Unfortunately not as exciting as it looks - it’s just a standard 2 output module, but relabelled with his name. Any of the modules can be renamed by double clicking on the name within the editor interface, so you can e.g. label your oscillators to “mod osc” & “carrier osc” rather than all of them being called “Osc A”
I’ve got the G1R (about which that ebook is written) - it’s an incredible piece of kit. The patching interface is the best I’ve tried of any software modular and the sound is rich and raw, particularly when you patch in feedback. The knobs encourage a workflow of setting up a structure then exploring it, which you wouldn’t get with the G2E unless you had an external controller.