Hmmm, they're trying to explain it as an analog of the Casimir effect, but the specific paper was paywalled.
I was partial to Bohm and de Broglie because of a kooky idea I had about trying to explain the effect of increasing mass as reducing the spread of the temporal portion of a pilot-wave type of interaction, as I was trying to work back from relativity to arrive at quantum mechanics. There are various problems there though, not least of which was the appearance that hidden-variables were disfavored in plausible explanations of reality.
Setting aside my kooky ideas though, assuming the theoretical explanation given is accurate that could be really exciting, like, we might end up discussing ways to arrange components based on this effect to produce a negative energy region without the requirement of handwavium exotic matter, and that leads to wormholes.
What effects do we get if we arrange a ring of these Q-thrusters?
What does reversing the orientation do, if anything?
If this isn't a quirk of the design itself, could we optimize it with metamaterials?
How does the effect vary when changing the size of the Q-thruster?
What is the smallest possible version which exhibits this effect?