Jeff, too costly to produce, and it would have hefted (to read) like an unabridged dictionary - That Fat.
Simply impossible.
I was thinking (for that break point) in terms of STORY RHYTHM, and Peril's Gate is the tipping point - after the Maze, everything rearranges and converges - there would have been no 'bastard start' - no Fugitive Prince where people (some) 'assumed' the books were slowing down and sprawling.
It would have contiguously built to that point, and then, vol II would denoue it all.
Given the physical constraints of the SIZE of this work, it was not possible - I don't think I did a bad job of engineering the breakpoints to subdivide. I didn't just write until I had to stop. Each book's start and finale was re-crafted to work in sections.
Arc III had the largest leaps to cover.
Arc IV's vol I is straight up on schedule, so I have no worries it will fall in as planned.
And Arc V is all denouement.