I don't believe grub has ever been successfully patched to
support this: I'd welcome it if they did, though i'm not testing hardware and kernels these days.
grub-reboot — Set the default boot menu entry for the next boot only. grub-set-default — Set the default boot menu entry for GRUB.
Set the default to be latest-1 and define one time boot with latest.
Best Regards, Strahil Nikolov