We study a minimal three-sector mediated system and derive the second-order effective dynamics on the outer subspace. We show that mediated transport is governed by an inverse detuning structure, while asymmetry between transport channels is controlled by detuning imbalance. This produces structural suppression of reconstruction under restricted return operations, while exact reversibility remains preserved under full unitary inversion. The complete proof and unification with the forward dominance theorem is given in the companion paper (Theorem 11b (Unified), DOI: 10.5281/zenodo.19380323).
Craig Edwin Holdway (2026) studied this question.