My post #5 has a syntax error in the init of minirt.gz.

line 744 "fi" unexpected (expected "then")

What a grand way to demonstrate a syntax error.

Here's an example the magic required to edit the init in minirt.gz
The really crucial lines are spaced apart from the others.

cd /
sudo su
mkdir fresh_tmp # because you need a clean workplace
cp /mnt-system/boot/syslinux/minirt.gz /fresh_tmp
cd fresh_tmp
gunzip minirt.gz

cpio -imvd --no-absolute-filenames -I minirt

sudo leafpad init
( here we change init and save )
rm minirt # you don't want this in the gzip process

find . | cpio --quiet -o -H newc | gzip -9 > minirt.gz

chmod +x minirt.gz # because the original was executable
cd /mnt-system/boot/syslinux
mv minirt.gz minirt.gz.orig # this may come in handy
cd /fresh_tmp
mv minirt.gz /mnt-system/boot/syslinux
( here we should probably erase our tracks in fresh_tmp
before it becomes a permanent fixture )

Be aware, any syntax error in init will bring your boot process
to a screeching halt. As I have just demonstrated.

It may be noted that the technique of post #1 comes in handy in
cases like this.
I will now belatedly study compound if/then syntax. More later.