Oh, that's a good point about finding Wang Zheng, I had forgotten about that! Idk if the Wu Tian'en instance counts, because there's no telling whether he could have done anything useful with it, but I can see how it would feel that way to him.

What strikes me, though, is that all three instances you name are with the Sundial. Why doesn't he try it again later, and instead go for the Awl? Do you ahve any theories?