No need for hardware KVM to reboot your encrypted server
SSH_UNLOCK allows remote SSH unlock for Full Disk Encryption FDE1 case.
On a bare GNOS Core the key
/etc/initramfs-tools/root/.ssh/authorized_keys references the key at
GNOS CLI includes OpenSSH, in that case the default user key at
$HOME/.ssh/id_rsa.pub will be used instead.