That is not legal in my state. If it overhangs by 18" or more you are getting a ticket.You are thinking of the wheel well intrusions the wrong way. In the Cybertruck, the entire bed appears to be as narrower than the wheels. So you are losing space. Probably around 50 to 55 inches wide. Easy enough to confirm with the math. If the entire truck is 79 inches wide, and each wheel/tire takes up about 12 inches, that leaves you with about 55 inches between the wheels.
In regards to carrying 12' lumber in a 6.5' bed, just toss it in hanging over the tailgate with the tailgate up. Throw a strap over it so it doesn't slide around side to side and add a red flag on the end if you want to be technically legal.