This record provides the final numerical validation suite for the IDMR–YM framework (v3.4). It documents a rigorous three-phase validation process: (1) Convergence & Norm Stability: Confirming second-order convergence ($p \approx 2.0$) and norm conservation using absorbing boundary masks. (2) Energy & Phase Coherence: Demonstrating that the IDMR field acts as a coherent energy reservoir with stable phase evolution ($\delta \Phi < 10^{-2}$ rad), supporting the PNGB stabilization mechanism. (3) Parametric Robustness: Identifying a critical damping threshold at $\alpha_{crit} \approx 0.01$ for vacuum stability. These results confirm the computational viability of the 'Induced Mass' mechanism and provide definitive constraints for the coupling constants discussed in EPJC-25-12-332.This record provides the final numerical validation suite for the IDMR–YM framework (v3.4). It documents a rigorous three-phase validation process: (1) Convergence & Norm Stability: Confirming second-order convergence ($p \approx 2.0$) and norm conservation using absorbing boundary masks. (2) Energy & Phase Coherence: Demonstrating that the IDMR field acts as a coherent energy reservoir with stable phase evolution ($\delta \Phi < 10^{-2}$ rad), supporting the PNGB stabilization mechanism. (3) Parametric Robustness: Identifying a critical damping threshold at $\alpha_{crit} \approx 0.01$ for vacuum stability. These results confirm the computational viability of the 'Induced Mass' mechanism and provide definitive constraints for the coupling constants discussed in EPJC-25-12-332.