Three examples of eROSITA X-ray spectra of the NLS1s in our sample. Left: folded count rate spectrum (purple crosses) and background spectrum (shaded regions); middle: unfolded spectrum and the best-fitting power-law model; right: unfolded spectrum and the best-fitting model including a blackbody component accounting for the soft excess emission. See Section 4 for best-fitting power-law models and Section  E for more detailed soft excess modelling.