Forward Modeling of H₀ Estimator Drift: The Mirage Operator and the Non-Existence of a Universal H₀

The Hubble tension (H₀ tension) can be formulated as an estimator-drift problem: it compares H₀ estimators inferred in finite domains under distinct observational procedures. The non-commutativity between dynamical evolution and inference operators established in Prevedello (2026, doi: 10. 5281/zenodo. 18642415) implies that observational estimators do not directly recover the underlying dynamical rate. This work tests MRUV cosmology by constructing the complete forward operator mapping dynamics onto observables, including: (i) MRUV dynamics R (t), (ii) null geodesic propagation and observable redshift in a metric with temporal lapse A (t) and dimensionless photonic scale factor B (t) = R (t) /Rₘax, and (iii) finite-window inference through an estimator Π producing Ĥ (W). The redshift relation (1+z) = (A₀B₀) / (AₑBₑ) couples temporal lapse to expansion, generating a class of observational projections beyond standard assumptions. A minimal physical closure is imposed directly at the level of observables by requiring: (1) correct low-redshift distance scaling, and (2) minimal curvature of the luminosity distance DL (z). This prevents spurious estimator drift induced by artificial curvature in the observable. Under this closure, forward modeling yields a drift coefficient βₚred = -7. 23 ± 0. 86 km/s/Mpc, in comparison with Pantheon+SH0ES observations βₒbs = -9. 8 ± 1. 2 km/s/Mpc, corresponding to a difference Δβ = 2. 57 km/s/Mpc and a tension of 1. 7σ. In addition, we establish a general structural result implied by the operator formulation: there exists no scalar estimator of the Hubble parameter that remains invariant under changes in observational window or projection operator. The Hubble constant must therefore be interpreted as an operator-dependent and scale-dependent quantity rather than a universal constant. This dependence arises generically in any cosmological model with nonlinear luminosity distance, including ΛCDM. These results show that part of the observed H₀ tension can emerge from the structure of cosmological inference itself, while MRUV provides a concrete physical realization of this mechanism through forward modeling. This work operationalizes the Non-Commutativity Theorem (Prevedello 2026, doi: 10. 5281/zenodo. 18642415) and completes the methodological closure initiated in Prevedello (2025, doi: 10. 5281/zenodo. 17917734). It establishes both a concrete physical test (MRUV compatibility at 2σ level) and a general theoretical result (non-existence of universal H₀ as an operator invariant).