Hello, there is no specific information available regarding the certification of XPAF version 9.0 for IBM Z16 processors under z/OS. To obtain the most accurate and up-to-date information regarding XPAF's compatibility and certification for IBM Z16 processors, it is recommended to reach out to Xerox or consult their official documentation or support channels. They will be able to provide you with the latest information on compatibility and certification for XPAF on specific platforms and operating systems.