FMR offset as a function of stellar mass and the projection of minumum scatter. Left-hand panel: deviations from the FMR plotted as a function of stellar mass. Symbols are as in Figs. 5 and 7, with individual points (and M_⋆–redshift bins) colour-coded according to redshift. At fixed stellar mass, JWST galaxies are preferentially offset towards lower O/H with incresing redshift, and a similar trend is also seen with increasing M_⋆ in the highest redshift bin. Right-hand panel: two-dimensional projection of the M_⋆-SFR-O/H space in the O/H vs μ = log(M_⋆)-αlog(SFR) plane, assuming the parametrisation for high sSFR (log(sSFR/yr⁻¹) > −9.5) galaxies inferred from the analysis of the SDSS sample (α = 0.65, Curti et al. 2020b). Most of the individual galaxies, as well as the median values in the M_⋆-redshift bins, are offset below the relation, further suggesting that the local FMR parametrisation does not hold at the very high-z and low-M_⋆ probed in this work.