I am actually inserting kickstart files within the iso image,. I've had this working with legacy mode for quite a while, with multiple entries in isolinux.cfg, but have been struggling to get this to work with UEFI.

Can you point me to an example of what the efi/boot/boot.cfg would look like? Would I be putting the  menu items into bootx64.conf, or maybe grub.conf? If so, can you tell me what they would look like? Any help you can provide would be greatly appreciated.