you ignore reflection effects, and node hunting is all about the reflection effects.

I think node hunting could easily be about direct front/rear speaker interaction, not just reflections.

Are you saying that altering the mic's position between the front and rear speakers would have no node issues in a zero-reflection (anechoic) chamber? I think it still would.

I would think that if you took two speakers, had them play the exact same music (i.e, like a front and rear speaker would), and moved the mic different distances between them, then you'd get nodes just as easily as you would get them from reflections. What's the difference between a reflection coming from a wall that's 2 meters away, or a fresh identical signal from a speaker that's 4 meters away? In fact, I'd think you'd get more prounounced nodes because the direct-from speaker signal would be more pure than a reflection of the signal.