Abstract: For realistic noise having both a Markovian and a non-Markovian (temporally correlated) component, the combination of quantum error correction and dynamical error suppression offers a promising path to quantum fault-tolerance. In this talk, I will revisit the extent to which the foundational notion of a constant gate error remains valid in the presence of noise that is both temporally correlated and nonclassical, and whose impact is mitigated through perfect dynamical decoupling subject to finite timing constraints. By considering a minimal exactly solvable single-qubit model under Gaussian quantum dephasing noise, I will show how the fidelity of a dynamically protected gate can depend strongly on the applied control history, even when the system-side error propagation is fully removed through perfect reset operations. I will further show how this can be explicitly related to the evolution of the quantum bath statistics, when temporal correlations remain significant across multiple circuit locations. Only if decoupling can keep the qubit highly pure over a timescale larger than the correlation time of the noise, the bath approximately converges to its original statistics and a stable-in-time control performance is recovered. In closing, I will outline ongoing extensions to multi-qubit settings, along with implications for quantum hardware and error-mitigation design.