PSA: Good news, bad news, and worse news about the Great Sealing.
With the healing of Hazō's Medium consequences, his bloodline access has been restored and he has a clear picture of the Great Seal available to him. He waited several days to start looking at it and even then only very carefully, mentally 'looking away' before really taking in the entire thing. There were some minor issues at first but it's been a couple of weeks and he's now comfortable mentally 'examining' the seal as much as he likes. That's the good news.
The bad news is that he now realizes that, unlike every other seal he has ever seen, the Great Seal is three dimensional. The Iron Nerve stored the relative heights of each segment, the overall layout, and even the texture of the surface, suggesting that all of those factors were important.
The worse news is that no one that either Hazō or Kagome have ever heard of has so much as mentioned the idea of a 3D seal. It's possible it's even against some of the standard lore, meaning that lore is wrong. That means there is no precedent for how such a seal interacts with the Iron Nerve. Hazō doesn't know if there are important factors that the Iron Nerve didn't store, or if some of the ones that it did store are actually not important.
One more tiny bit of good news: The Iron Nerve did in fact store parts of the seal that were occluded from the angle Hazō was looking at, so he's fairly sure that his mental image includes the entire thing.