The z/Server scheduler is no longer required in Enterprise Developer 5.0 as the MFA Server now supports z/Server functionality via the MFA TSO Application Server. If you are installing Mainframe Access Server 5.0 and all of your clients are running Enterprise Developer 5.0 then you do not need to configure the z/Server scheduler, instead you should configure the MFA TSO Application Server. See Migration information for more information.
z/Server is now deprecated, and marked as such in the documentation. The only reason to configure the z/Server scheduler is if support for clients earlier than Enterprise Developer version 5.0 is still required. Micro Focus recommends keeping all Enterprise Developer clients up to date and in sync with the Mainframe Access Server version.
If you have a mixed environment of clients running Enterprise Developer 5.0 and clients running Enterprise Developer 4.0 or earlier then you will need to configure both the MFA TSO application Server and the z/Server scheduler.