Same as Figure 4, but with the SDSS density contours as the sole local reference for simplicity. The high-z sample is represented with circles, with no distinction between different datasets. Left panel: High-z sample colour-coded by ΔMS, i.e. the deviation from the parametrised SFMS from Popesso et al. (2023), computed at each specific redshift. Right panel: High-z sample colour-coded by stellar mass. The gradient angle of the M_* trend within the plane is shown as a red arrow, visually representing the finding that N-enhanced galaxies are preferentially associated with lower stellar masses.