Tinkers takes shape (half-way through)

About halfway through "Tinkers," Paul Harding (wisely) sets himself free from the structure he'd established - narrative passages alternating between the contemporary (90-year-old George Cosby in his dying days) and the past (George's father, Howard - not his grandfather, as I'd said on previous posts - on his rounds as a Yankee Peddler circa 1915) - and successfully braids the two strands of the story. The plot of the novel begins to crystallize, as we see more scenes of Howard and George interacting during George's childhood - in particular, a dramatic, seminal scene in which Howard falls into one of his epileptic fits, George tries to keep his father from biting his tongue, father bites George's hand, mother takes George to doctor for stitches, doctor suggests that Howard must be institutionalized, which I guess was common practice for epileptics in the early 20th century? We will begin to see where this leads - maybe Tinkers will have a conventional plot after all. I don't believe that "conventional plot" is essential to all novels, but I do believe that a novel must have a shape and a design and that all elements in a novel must contribute to its shape and serve a purpose. I also believe that no work of art should have any extraneous elements. As noted in previous posts, Tinkers, for all its strengths, at times seems to be a gallery for the exhibition of Harding's talents - and I know that was not his intention - but as the book moves along it does begin to take shape, and we'll see how it develops and where Harding leads us.