Upper panel: comparison between the abundances relative to H₂ in our objects and the peak surface abundances in the models from Garrod et al. 2022 (Table 17). Lower panel: comparison between the abundances relative to CH₃OCH₃ for O-bearing molecules and CH₃SH and relative to CH₃CN for cyanides. Each source is represented by a different colour. The models are represented by three symbols. The grey area represents a factor 5 scatter from the average model values.