Due to the kernel options problem, which I'm not clear would be solved by
removing grub/grubby, I decided to try to use systemd-boot to
bootstrap GRUB.
The only requirement I can find is that it needs to be on the same drive as
the ESP partition, so I'm going to convert the 1GB NEW_ESP partition I
created to a grub /boot partition and see if after I install systemd-boot
to the original ESP partition, grub will be found.
Thanks,
Richard