Entertaining discussion on ECW on the wildly guessed energy source of the famous new Ecat SKLep…seems a new Axil Axil is born 😅
QED's central catechism is vacuum-produced gauge-boson mediators exchanging ambient quantum momentum (h-bar) between interacting masses, charges or spins (as opposed to these force carriers being emitted or absorbed by interacting particles themselves). That is, electric charges do not 'interact', and nor do masses, but via the intermediary of these trades of quantised ambient momentum spontaneously produced on-demand from vacuum, at fixed time rates of change as set by eg. the gravitational constant or the EM / fine-structure constant, alpha. Thus momentum and energy symmetry of such interactions is dependent on time/velocity symmetry of inbound vs outbound legs of a closed-loop interaction. If this time-symmetry is broken, closed-loops through static fields yield non-zero net momenta. Accumulation of such momenta at fixed unit energy cost is an inherently OU process, placing the input energy workload in a divergent inertial frame, resulting in energy gains equal to the half-square of the 'velocity' component of the anomalous momentum delta.
Besides, there's a whole variety of Casimir-type effects you've neglected