Comparison of XGBoost metallicities with GALAH DR4 iron abundances. All of the panels include the selection described in Sect. 2.1 as well the flag_sp==0 selection from GALAH. The colour code is XGBoost T_eff, and the numbers within each plot indicate the mean offset and dispersion of the difference. Top: all stars with [M/H] > −1. Bottom: LMR stars only, i.e. stars with metallicities above the ISM’s one at their guiding radius.