Comparison of O/H abundances in the sample of star-forming regions considering a homogeneous temperature structure (t² = 0) and considering temperature variations (t² > 0) following the empirical relations derived by Méndez-Delgado et al. (2023a). Red dots indicate the O/H abundances determined from the ultrafaint O II-RLs, which are insensitive to temperature. The solar O/H abundance from Asplund et al. (2021) is shown for reference.