IV.T148 — m_μ/m_e Best NLO Formula: ι_τ⁻⁴·⁹⁶ at +307 ppm

The best NLO approximation for m_μ/m_e from a 14-formula scan (Wave 3A lab, 50-digit precision): ι_τ^(-4.96) = 206.8318 at +307 ppm from PDG 206.7683. Effective exponent 4.96 = 5 − 0.04, where the gap 0.04 ≈ 1/25 lacks a first-principles structural identification (see IV.R398). All simple analytic NLO corrections tested (κ_ω, κ_D², CF-window W₃(4)=5, continued-fraction a₂=13) remain outside 1000 ppm. The exponent back-solve is the only τ-effective result; the correction factor identification is OQ-C5a.