Photo-z dispersion in equally populated magnitude differential bins to i_AB < 23 (top) and equally spaced redshift bins to z < 1.5 (bottom). Each line corresponds to a different training procedure (see Sect. 3.2). While the black line corresponds to a baseline training, the other coloured lines include MTL (red and green lines) and data augmentation with photo-zs from the PAUS+COSMOS catalogue as ground-truth redshifts (blue and green lines).