Corner plot of metallicity estimates for the crossmatched VMP subsample (∼500 stars). Diagonal panels show the one-dimensional distributions of [Fe/H]_RVS and [Fe/H]_SP from the DESI RVS and SP pipelines, the metallicity [Fe/H]_GaiaXP derived by L. Yang et al. (2025) from Gaia XP spectra, and the model-predicted [Fe/H]_model, with the median and 16th/84th percentiles indicated in the panel titles. Off-diagonal panels display the corresponding two-dimensional distributions for each pair of metallicity estimates.