V.R464 — Phase-Shift Sensitivity

ℓ₂ α-insensitivity is a structural stability result: δφ₀=ι_τ/10 is sole content. ℓ₃ residual (−6250 ppm) driven by z_eq excess, not α. Fixing ℓ₃ requires ω_m NNLO or Boltzmann solver. α remains conjectural.