Welcome to the Batocera world, and congratulations for the double win.
First, to get an Odroid H2 in the one day sellout. 🙂
And second, you have found the path of light to Batocera, more evoluated
as Recalbox. So just classify Recalbox as a very short experience of frustation.
First, you should install Batocera (5.19 is ok) on your sd card.
Second, configurate your bios as much as it is possible to boot from USB in
legacy and try to switch off UEFi if possible, what is not possible with some bios.
If you dont arrive to boot Batocera after this, comes the second solution.
I had the same problem with my Beelink X55 and some other people with a Gemini Lake
chip as J4105 or J5005. What I can tell on the borders having now also an Asrock J5005 Itx, this processors are very quick, much more quick as I expected.
Now to the solution anyway if before you dont arrive to make your board work.
Just download from my site this alternate Uefi boot loader http://zclub.eu/Efi.zip and delete all the files in the SD Card folder /boot/efi/ and replace them with the new unpacked files.