  To numerically evolve the full Einstein equations (or modifications thereof),
simulations of cosmological spacetimes must rely on a particular formulation of
the field equations combined with a specific gauge/frame choice. Yet truly
physical results cannot depend on the given formulation or gauge/frame choice.
In this paper, we present a resolution of the gauge problem and, as an example,
numerically implement it to evaluate our previous work on contracting
spacetimes.
