Your tool seems to understand the gist of differential cryptography better though. You can track a 1-bit change or 3-bit change to "M" and see how it propagate

Your tool seems to understand the gist of differential cryptography better though. You can track a 1-bit change or 3-bit change to "M" and see how it propagates through the SHA256 rounds in your tool. ---------- So your tool is probably better at understanding the underlying design of SHA2. We know that SHA2 was created well into the era of differential-analysis for example, so the designers would have inevitably done analysis similar to how your tool works.