(a) χ² between the RAVE observation and the best-fit spectrum in ⟨3D⟩ NLTE around the oxygen triplet at 8446 Å, provided by TSFitPy, as a function of S/N for 8018 RAVE stars. (b) ⟨3D⟩ NLTE [O/Fe] uncertainty distribution (solid black line). We also show the individual distributions of ⟨3D⟩-NLTE uncertainties due to uncertainties in T_eff (blue), log(g) (orange), and [Fe/H] (green). For comparison, we show the [O/Fe] uncertainty distribution in 1D LTE (dashed black line). (c) ⟨3D⟩ NLTE [O/Fe] uncertainties vs. S/N. (d–f) The ⟨3D⟩-NLTE [O/Fe] uncertainties as a function of T_eff, log(g), and [Fe/H], respectively.