Wm, I think it is a little more complicated than that although you are on the right track. In my opinion The trick is vacuum flux are moving on the time axis so from their perspective your "box" has 6 sides -they manifest while traveling from the future side to the past side while the other 4 sides located in 3D space appear flattened out to a "width" = to what we perceive as the "present". Casmir "plates" can force these fluctuations to shrink, squeezing through the lattices to achieve "equivalent" acceleration from our perspective just like a large gravitational mass but on a mesoscopic scale. It is the tiny cavity between the plates that produces something the macro scale cannot, "equivalent deceleration", The squeezed fluctuations accumulate a pressure behind the plates that is suddenly released by the cavity forming a fast moving vortex/venture. Instead of slowing time by opposing fluctuation flow, the cavity accelerates time flow.
You can ignore the temporal and conservation of energy aspects if you put it in terms of catalytic action which really just disguises these terms but avoids a lot of controversy. This puts your present description on the right track, you have a time machine in the form of a rigid catalyst, you have the uncertainty principle driving gas law to keep atoms in motion, you have natures preference for a diatomic state and apparently you also have natures resistance to molecular motion in a catalytic environment but we know disassociated hydrogen can make a non radiative translation to fractional state. This suggests that a fractional molecule formed >From these translated atoms also opposes catalytic action (change in Casimir force) so that the atomic motion of gas law provides relative motion with the stationary plates producing changes in Casmir force which break the bond - It is during this period while vacuum fluctuations are accumulating boundary conditions in opposition to the covalent bond that the potential for reactionless drive exist. The Plasma is produced at the moment of molecular formation locking the atomic fractional states proportional to local plate geometry, the molecule then moves based on gas law with the fractional states trying to change but opposed by the covalent bond, If this "post plasma" but "pre bond break" gas can be driven preferentially on one axis it may provide the elusive "ether oar". If I had the ability to create black light plasma I would put the device in a nonferrous balance scale and change the opposing weights while the unit was on and compare to changing the weights while the unit is off - My theory is that the "settle" time would be much slower with the plasma on then off because of these increased boundary conditions. Regards Fran