I've found a reply to another post from ONYX as I was searching for the answer to, The answer is "THERE IS NO DIFFERENCE OTHER THAN PACKAGING" nothing to do with internal storage of anything to do with the device full stop it's just the name was changed for international sales. Please see following link and you will find someone with the same question and see onyx answer the question.
https://ereader.store/en/13-3-inch-s...-max2--23.html