Hi John, I didn't manage to get network booting using UEFI without grub but with syslinux running. I copied the syslinux.efi and ldlinux.e64 into my tftp directory. Using tcpdump I see that the UEFI is getting the syslinux.efi file (even I use a different name and a symlink). I do not see any request for the ldlinux.e64 file.
In your setup, are you really getting syslinux with UEFI use the config from fai-chboot? Maybe your computer has still CSM (the legacy mode) enabled, and you are still using pxelinux. -- regards Thomas