Gyges Yep, that sounds right. I’ve just gone and tested these commands myself on my ordinary x86_64 PC, and it worked successfully. But still, I feel that the instructions seem to be going a bit overboard.
Could you try deleting the overlay (the one in boot, just insert your SD card/USB into another computer and delete the file named “overlay”, if you don’t know what I’m talking about just reflash your SD card/USB) and running just steps b. and c.? That is:
mount -o remount,rw /boot
echo "es.resolution=1280x800" >> /boot/batocera-boot.conf