You might be right. But here's the problem: in my recent experience there's either going to be a tiny knock or some drag. I suppose if I were a professional I could thoroughly diagnose, make frame/fork modifications and press a new headset into every bike. But I have to make some compromises.

PS: One of my concerns is that my special test exerts an "undue" force on headsets and is revealing tiny knocks that exist naturally in most headsets. (Or perhaps causing a tiny knock somewhere else that I can't locate.) I do believe my test applies more force to the headset than standard the "lock 'n rock" method. But if it's true that zero play is what I'm after, then recently I've had to go tight to achieve it.

My spidey sense tells me there will be skepticism on this point. That's OK -- I'd be skeptical too.