/mnt and boot at /mnt/boot. Then in the manual partition menu I set each respective partition to System and Boot, then ran the installer. Afterward, I updated /mnt/etc/fstab and /mnt/etc/crypttab according to my disk layout. I updated mkinitcpio, modprobe and GRUB configs to ensure the disk would be unlocked at boot, then ran arch-chroot to ensure those settings were applied to the boot partition. /boot/efi and rerunning mkinitcpio and grub-install, but it still didn't boot.