Regarding the two drafts that looked similar in the threading, tie-up and treadling, but were not the same in structure, I was trying to follow what Rose told me in her comments, but I thought I was going to go blind staring at the two drafts. As if she was standing behind me, she recommended I take out the color effect out of the drafts, and now I see that the structures are not identical.
This is the 7-shaft Corkscrew example.
This is the 8-shaft Shadow Weave example.
I'm not sure where I am with the definition of Corkscrew, but at least I got these two sorted, and I think the bottom one is, ummmmm, not a Corkscrew. Don't I, Rose?