Since extipl uses unallocated sectors on the disk, and not a separate partition, it can't be used on disks with gpt partition tables. (The usually unallocated 62 sectors at the beginning of a disk with an ms-style mbr partition table contain the larger gpt partition table of 32 sectors.)
Ideally we would have a package which will create a partition and install the boot partition selector there.
-- André
