Have you tried the VGA image and Etcher or Rufus to a USB? I was not able to get the DVD version to work with either Etcher or Rufus, complains that it is not a file system (or something like that).Also have you tried a Ventoy USB with either (both) the VGA and DVD? One of these works, but I forget which image lets my computers boot.I used Rufus with the VGA img to a USB and this worked to boot and install to my computers, I've done three this way and one of them about 5 times now while I got my process documented.I haven't looked into the Nano image yet, I may need to do this just to round out my knowledge, I have more install attempts to make on my test stuff just to work out issues before I build my long term device.
I would probably use either an nvme drive in the m.2 slot (says SATA not supported) or use a 2.5 inch SATA drive from one of the connectors. At least you could test it this way.Are there any BIOS updates or EMMC firmware updates? I wonder if there is a different brand of EMMC that would work.I wonder if something like this would let you write the Nano version directly to the EMMC https://www.amazon.com/ODROID-USB3-0-eMMC-Module-Writer/dp/B07BHQ615Q
Is there anything in the BIOS that might be protecting the EMMC?