That isn't necessarily a problem; Debian handles this by means of a kernel postinst hook that copies the newly-installed kernel from its installed location in /

That isn't necessarily a problem; Debian handles this by means of a kernel postinst hook that copies the newly-installed kernel from its installed location in /boot to /boot/efi/EFI/DEBIAN (or wherever gummiboot expects to find the kernel, I can't remember off the top of my head). That systemd refuses to support anything other then EFI at /boot puts it into opposition with existing practice (as seen in Debian, Ubuntu, Fedora and SUSE).