Don't know if I buy the whole "Faster than the speed of light" theory of expansion.
Look at it logically. If the time continuum slows as velocity increases & time stands still at terminal velocity, what happens when terminal velocity is surpassed? Isn't that when time would work in reverse? Where would the energy come from to do such a thing? If the direction of expansion is 3 dimensional, or whatever, then wouldn't the opposite be 0 dimensional?
Big question is, is expansion a result of pushing or pulling. One would lead to one train of thought, the other an entirely different one.
Kinda like a piston in an ICE, is air mass being drawn in or forced in? We know with gravity it is being forced in, but if the energy for terminal velocity can be surpassed, it needs more energy than the particles were accelerated with to begin with, right? "So what is pulling them faster?" Should be the derived question. Looking at it this way, even with gravity & mass present, the piston still needs to move or else nothing happens.
The issue is still entropy. Or non adiabatic existence. So if the adiabatic model is seen with no overlap of time & energy, the only way to operate beyond adiabatic would be for the energy change to be opposite of time wouldn't it?
ETA: In a given example of the ICE, the mass acceleration is dependent on piston velocity via change in pressure over time. Faster acceleration rates of a piston transfer to a higher rate of change in dynamic pressure with in the intake track. We can force more air mass in by two main methods for a given mass-flow capability: Change static pressure or increase piston velocity. Both require more energy.
Now I see the variable here is mass density. We know that all mass breaks down eventually to hydrogen, so where does the mass go. "Out there some where" is all I can come up with.
OK, if that lost mass is translating to more energy via the proposed matter/antimatter reaction, what happens then when the system runs out of mass, or anti-mass?