Same as the third panel of Fig. B.2 in the original article, but with the correct sensitivity limits used to compute the surface brightness values of the horizontal dashed lines. These horizontal lines denote the minimum surface brightness required to achieve a certain detection significance (S/N) using JWST/MIRI at a wavelength of 21 µm. Red lines are for an exposure time of t_exp = 1 h, blue lines for t_exp = 5 h.