nature makes particles behave according to curiously rigid rules.
Huh ... doesn't sound at all like that Gaia chick.
I agree that this experiment doesn't directly address other energy levels (although it handles the edge condition). The effect will be less at higher energy levels. As an analogy, the two-slit experiment (the hypothetical, intro quantum theory experiment that shows that electrons appear to be in multiple places at the same time) is done with particles, where the effect can be noted, not baseballs.
Physical theories can be verified under different conditions, but not proven in the mathematical sense. Remember Mr. Spock's: "We may be in a region of space where our physical laws do not apply."
BTW, to show I'm not all "math" and "guy", I saw "The Music Man" recently. You came to mind when the mother blames her daughter's singleness on "her Irish imagination, her Iowa stubborness and her library full-of-books."
But I forget why.