Left panel: theoretical SL profile pB plus an additional component modeled by Eq. (1) with η = 0.25, μ₀ = 21.04, α = 6.20 (SL profile pD) and respective iFIT fit. Right panel: pD plus an extra luminosity excess in the faint end of the SL modeled by the polynomial equation μ(R) = 0.148 ⋅ R² − 5.960 ⋅ R + 84.180, (SL profile pE) with the iFIT solution overplotted. Overplotted dashed-dot purple lines display the additional components.