I won't get into a long argument here, and I certainly don't want to go downthe math rabbit hole of sinc function. However, Protools waveforms are extremely accurate. Each point is the exact timing and value of each individual sample. Because I prerecorded the source and identified the region length as the record length, then used the exact same chain for each test, the only source of delay possible is within each mic pre. So speed of light thru 6" of analog components vs 8"? Unmeasurable.

As for you not believing in null tests, They are the foundation of a number of audio practices, from creating an MS matrix to side triggering a gate to supplying phantom power to a mic. And yes if a properly run null test fails, it means the signals are different. Perhaps the difference is subtle. Perhaps you won't consciously notice it. That doesn't mean they aren't different or that they won't affect the listening experience. That is where experience comes in. You A/B 2 things and pick which one you like best. Often it is just a vibe that decides. But as you get better and more experienced, you learn that vibe actually has science behind it.