Comparison of luminosity (solid lines) and effective temperature (dashed lines) for four models computed with different choices of T(τ) relation (top-left). The displayed quantity is the relative difference of L or T_eff, with respect to model computed with the Eddington T(τ) relation: δX ≡ (X_T(τ) − X_Edding.)/X_Edding.. Top right panel is the same as top left panel but, instead of X ≡ s_ad, we display the absolute difference. Indeed, with s_ad being defined up to a constant, the relative difference would have no meaning. Also, Δs^presc is in the units: 10⁹ erg g⁻¹ K⁻¹. Bottom left panel: evolution of α_MLT for different T(τ) relations: Eddington (blue), Vernazza et al. (1981) Model-C (orange), Krishna Swamy (1966) (green), and Ball (2021) (red). Bottom right panel: temperature as a function of the pressure for the same four final models at solar age.