V.R478 — Sensitivity of Spectral Coincidence

Sensitivity analysis of the ε₁ ≈ λ_{1,1}(τ) spectral coincidence. Derivative dλ/dι_τ = −2ι_τ⁻³ ≈ −50.3 (1% shift → ~5% change). Critical value c = 1/√(ε₁−1) ≈ 0.3423, only 0.28% from ι_τ. Gap is structural, not numerical uncertainty. Whether an operator normalisation identification closes this gap remains open.