We compute a two-phase stability map of the COCM oscillatory parametrisation in the space of orbital eccentricity e and dataset size n. Using mock catalogs with Gaussian noise (A₀=0. 091, φ=−0. 956), we measure the fraction fS of free optimisations that recover ωᵦ = 11. 1991±1. 0. The regime boundary is found at ncrit = 12. 8 ± 1. 5, nearly independent of e. DR2+CC (n=14) lies marginally above ncrit under Gaussian noise — the non-recovery observed in real DR2 data is not primarily a statistical-resolution effect but reflects displacement by a compact high-tension substructure (ELG2, −13. 4σ). This result formally revises the qualitative interpretation of NT16 §2.
José Luis Vázquez González (Fri,) studied this question.