As far as I remember, you have to make sure the bootloader's kernel is
at a sector that LILO can access. GPT is too new for LILO. You also
have to provide space where the bootloader saves its second stage,
always if my assumption that it uses the same mechanism used by legacy
GRUB, is correct.

So, according to me, you should leave the very first partition next to
the initial GPT headers free and unformatted. Use a very small
partition space.

All this if from memory which often is wrong with the passage of so
many years since I last used LILO and installed GRUB. GRUB works on
GPT formatted disks under a UEFI system.