Left: comparisons of the input label T_eff for our CNN (APOGEE DR16 labels) with the IRFM temperatures of Steinmetz et al. (2020b). Mean difference and scatter are indicated in the top-left corner. We also show a residual plot and an histogram of the difference. Middle: comparison of the labels T_eff trained by the CNN with the IRFM temperatures of Steinmetz et al. (2020b). Right: comparison of the T_eff values derived for our whole observed data-set (for S/N >  20) with the IRFM temperatures of Steinmetz et al. (2020b).