Hi,
refind-efi (not in AUR anymore)
https://forum.obarun.org/viewtopic.php?id=1333 same problem, see if you can apply the temp solution till Eric (the author of obarun-install scripts) is back and edit the installer pkg list and make the correction.
If the installer stopped and exited without finishing you can restart it so it can finish. Did it ask you for you username and password? Only when you see "installation complete, you can now reboot" was it finished. Is the target partition still mounted on /mnt ? Remount it and rerun the installer ... something went haywire somewhere.
Yes, when you execute 66-tree -n boot a boot tree is created in the system, when you use 66-enable -t boot boot@ sysname then a boot module is enabled on tree boot.
Trees are groups of services that are meant to start together.
If you mount the target and access it through arch-chroot /mnt run 66-intree -g and please past the output here. If you see a boot tree and a long series of boot services active, you have a kernel, and the boot-loader is configured, then you should be able to boot. If something sticks ctrl-shift F12 and use your username and pw, not root. If a boot tree is not setup you will end up in kernel panic.