I did not carefully review all the reference counting or go over everything with a fine-toothed comb but I did go over the whole thing and followed along with the structure.

Overall this looks really nice. I think there are some clear paths to improve it, but that's always going to be the case and this is already far enough along that once we have some basic docs written we can try inviting people to test it and start thinking about a NEP to do something about np.128.