As much as I've read the Zhuangzi, passages still seem to offer themselves afresh with unmined riches. When the shoe fits, the foot is forgotten. Alan Fox suggests this as an entry way into our understanding of wuwei. When life fits, our responses require no second-guessing.
"Chu the Artisan's swooping freehand arcs could match the lines made with compasses and T-squares, for his fingers transformed along with the thing he was making, his mind never lingering to check or verify." (Zhuangzi 19; Ziporyn) Chu's fingers let the lines let them make the lines. The lines drew themselves. Had it been otherwise, had he hesitated, had he worried about outcomes, the magic would have been lost. Perhaps wuwei is living as Chu draws lines.
"Hence, his Numinous Platform was unified and unshackled to any one place. The forgetting of the foot means the shoe fits comfortably." We needn't get all weird and esoteric about this. The 'Numinous Platform', like the 'Numinous Reservoir', is the self, your precious mysterious self that this is all about. Have we ever left that road, that this is about us, our enjoyment of life? How could we ever forget that, the whole point? That would be to be "unable to forget the forgettable, and instead forget the unforgettable — true forgetfulness!"
Similarly, the unified heart is no great puzzle; Chu had it when he did not pause, did not linger, did not doubt his hand's compliant swoop. Wuwei is letting life live through you; just as art lived through Chu. Like Cook Ding, when the deed was done, he awoke as if from a dream and looked around at what had been done. And, like Cook Ding, it took many years of practice to learn not to do it, but to let it get done.
Chu's hand was "unshackled to any one place." It was completely adaptable, could move as things required. But then it is the things that did it; had he done it, his hand would have been bound. Similarly, Zhuangzi suggests we "listen with qi"; and what is qi? — “An emptiness—an awaiting for the presence of beings." Or again, the sage’s mind becomes “the spring time of each being." Wuwei is the emptiness, the open-heartedness, that let things happen even as we make them so.
You can check out Scott's writings on Zhuangzi here.