Although it doesn't change the overall outcome with regard to booting straight from the FusionIO card, it also looks like I can get past the efivars error by passing "efi_no_storage_paranoia" at the kernel command line at install time.
Although it doesn't change the overall outcome with regard to booting straight from the FusionIO card, it also looks like I can get past the efivars error by passing "efi_no_ storage_ paranoia" at the kernel command line at install time.