Wow. I hope he's got some good strategies for dealing with the extreme sleep deprivation he's gonna get. Reading about Dick Rutan's airborne hallucinations and Charles Lindbergh's similar problems, it's (IMO) the major danger he faces.
I got to meet Jeana Yeager a few times, and some of the mid-flight gremlins they faced were astounding.
A GPS receiver and an autopilot.........
He appears to be energetic and willful. He should be fine. It's an adventure and dangerous, and if he fails at least he gave it his best.
Unlike the late Gonzo Journalist.