Manjaro and Garuda ISOs won't boot automatically

Heads can't boot Manjaro or Garuda ISOs. Both of these use variables in the GRUB configuration that Heads doesn't understand.

In this menu item, Heads would need to know the content of "$title" and that it will become "$2" in the menu entry. (This becomes part of the kernel file name and some important command line parameters. $kopt is not critical, it boots without it.)

    title=""
    for kopt in x86_64 $kopts  misobasedir=garuda root=miso:LABEL=GARUDA_DR460NIZED_RAPTOR quiet systemd.show_status=1 ibt=off; do
        if [ -n "$title" ] ; then
            title="$title $kopt";
        else
            title="$kopt";
        fi;
    done
    menuentry "Boot with open source drivers" --class=Garuda.x86_64 "$title" {# set arguments above with the editor
        linux /boot/vmlinuz-$2 driver=free nouveau.modeset=1 i915.modeset=1 radeon.modeset=1
        initrd /boot/amd_ucode.img /boot/intel_ucode.img /boot/initramfs-x86_64.img
    }

Start by locating the menu-item or GRUB configuration parsing code responsible for interpreting ISO boot entries; the issue does not name a file or test. Reproduce with Manjaro or Garuda ISOs and trace how the $title and $2 variables are handled. Done means both ISOs boot automatically while preserving the existing behavior for other images.