I think in the last video or 2 he finally had the revelation he needs to have a chance at success; he's found that the engineering must support the design, not control it. We'll see if it holds up.
He has had this realization several times over the years. Good luck to him, but at this rate I don't believe he'll ever manage to finish it, and if he ever does he still won't be happy with it.
Yeah, I'm not confident it'll hold. I figure someone will eventually make a marble music machine that's robust enough to tour, but I have doubts it'll be him.