Best-fit parameters of the outflowing plasma component (pion) for the five NICER stacked spectra sorted according to the intrinsic (unabsorbed) X-ray 0.3–10 keV luminosity (re-fit of the flux-resolved spectra with the RGS ISM model) as compared with the new RGS (open red circles) and NICER-only (blue star) results. The X-axis is inverted following the HID evolution from high-soft to low-hard states.