The Brinell 480-540 is approximately equivalent to Rockwell C 50-54 and that is hard.
For comparison, one of the hardest stainless steels 440C used for SS bearings typically hardened to Rockwell C 55. Tool steel (not SS) usually 58-62 Rc
But where the Brinell 480-540 numbers are coming from...
Is it a new chunk of optimism from Japan?
https://www.car-engineer.com/new-ryden-dual-carbon-battery-revealed/#:~:text=The dual carbon battery is,batteries, operating above four volts.
A brief compilation of what you will hear there in Texas
https://ca.video.search.yahoo.com/search/video?fr=news&ei=UTF-8&p=cybertruck#id=2&vid=90dd6b903b6e58a9dbf091a0c69f3559&action=click
When we will see the final design?
I would prefer never the final. Only the current model in production. Let it develop and modify to the new models the years ahead.