Well dual booters may want to reinstall windows sometimes so they need to install Grub from terminal on a live session. But lately I get errors doing this.
Correct me if I'm wrong but I think WUBI installs Grub so maybe its very simple just to add a boton to repeat that action than making a wizard. But If they can add more then that is good anyway. I pasted the EasyBCD like an example for a wizard.