Well, I've watched the video a second time, but I'm afraid I can't see much difference between the green and blue examples on my 27" screen. It answers a question I used to ask myself in my darkroom days. I never got round to testing it.
Nor am I quite sure about subtracting a few seconds here and adding a few seconds there. Why not simply do a fresh test? My heretic's mind keeps telling me that a couple of clicks in Curves would do it all, more simply, but that's unfair, because he is giving advice on his system of wet printing.
To be fair, he does say that testing is needed for other people's methods and situation. The changes he's making are very small indeed and would probably be overwhelmed by a slightly different negative.