Did you actually read my implementation?

You're looking at the 'x' block, which only applies if the point lies on the boundary. 

Trust me, I understand the point of the library, and for points that are clearly within the inner ring(s) at the given resolution, we short-circuit:

https://github.com/uber/in-n-out/pull/7/files#diff-068591b5cb8abf665e6104587d821d57R139