I did not understand Daves video @ 0.5 Ohm, neither. He also did not respond to my question about his experiment.
You can see an increased jitter at 50 Ohm, compared to the upper ranges, but for sure you're not in the residual mOhm specification, but instead in the % specification..so everything is fine..
What I have seen, and not understood, why it's quite tricky to make a REL (zero) setting.. even if the residual reading is quite stable, that will jitter around, and give some +/- 10 mOhm offsets after pressing REL by your hand.. Ian used the mobile app, which would be better.. can't understand that behavior at all.
And that really sucks, because a 1 mOhm resolution is really great for some applications, compared to other DMMs, but it has to be stable, and the zero has to work smoothly.
Frank