Dear Darnell,
in the MSMP workflow you have to customize the template as well. Add a notification template with template id "GRAC_EMAILRMDR_CUP", message class "0MSMP_EMAILRMDR_CUP" and document object (use a Z object).
In SPRO under GRC > Access Control > Workflow for Access Control > Maintain Customer Notification Message you can add the document object.
For the batch job define a variant for your MSMP process id (I assume SAP_GRAC_ACCESS_REQUEST) and define the settings (period, reminder, template).
Let me know if you need further help.
Regards,
Alessandro