No zero could possibly be a knight with such a rule. Although it might be interesting to try to build a Smullyanic Stream at some point, I think the more open dynasty rules are sufficient for an interesting puzzle. Note that Where is Black Cells (my Echolocation) is Nikoli's closest match to this puzzle, and that doesn't forbid 2×2 "whitespace" either.

Anyway, I'm glad you like the design. I took the task of making something worthy of the name very seriously, and I appreciate all the positive support I've gotten for it. - ZM