This paper investigates quantum decoherence in a class of models that interpolate between expanding (inflation) and contracting (ekpyrosis) scenarios. For cases resulting in a scale-invariant power spectrum, it is found that ekpyrotic universes lead to complete decoherence of the curvature perturbation before the bounce, in contrast to inflation, where recoherence has been observed. Although the purity can be computed for all couplings, the study also examines purity perturbatively, revealing that late-time breakdown of perturbation theory often occurs. A simple yet powerful late-time purity resummation is introduced, capturing the exact evolution to a remarkable level while maintaining analytical control. The cosmological background is shown to play a crucial role in the decoupling of heavy fields during inflation and alternatives. The paper explores the dynamics of curvature perturbations in a two-field model, considering both expanding and contracting phases. It derives exact transport equations for the evolution of the curvature perturbation and examines the perturbative treatment of the purity. The study finds that in the ekpyrotic scenario, curvature perturbations always decohere provided the entropic sector is not too heavy. The results show that the late-time scaling of the purity of a mode k is a tracer of the level of mixedness of the system's state. These findings corroborate previous studies on similar systems in the presence of sharp features. The paper concludes that the background evolution significantly influences the quantum information properties of observable degrees of freedom, highlighting the importance of the cosmological background in the dynamics of cosmological inhomogeneities.This paper investigates quantum decoherence in a class of models that interpolate between expanding (inflation) and contracting (ekpyrosis) scenarios. For cases resulting in a scale-invariant power spectrum, it is found that ekpyrotic universes lead to complete decoherence of the curvature perturbation before the bounce, in contrast to inflation, where recoherence has been observed. Although the purity can be computed for all couplings, the study also examines purity perturbatively, revealing that late-time breakdown of perturbation theory often occurs. A simple yet powerful late-time purity resummation is introduced, capturing the exact evolution to a remarkable level while maintaining analytical control. The cosmological background is shown to play a crucial role in the decoupling of heavy fields during inflation and alternatives. The paper explores the dynamics of curvature perturbations in a two-field model, considering both expanding and contracting phases. It derives exact transport equations for the evolution of the curvature perturbation and examines the perturbative treatment of the purity. The study finds that in the ekpyrotic scenario, curvature perturbations always decohere provided the entropic sector is not too heavy. The results show that the late-time scaling of the purity of a mode k is a tracer of the level of mixedness of the system's state. These findings corroborate previous studies on similar systems in the presence of sharp features. The paper concludes that the background evolution significantly influences the quantum information properties of observable degrees of freedom, highlighting the importance of the cosmological background in the dynamics of cosmological inhomogeneities.