The scatter points mark the velocity offsets resulting from a Gaussian fit to the binned CCF time series in WASP-189 b’s literature rest frame (v_sys and K_p listed in Table 1). Three bins are used pre-eclipse and post-eclipse. The scatter points’ colors correspond to different spectral templates: only-iron (at equilibrium chemical abundance), fiducial without titanium (our highest S/N template), and fiducial without iron and titanium. The purple line indicates our best alternative orbital fit compared to the literature, for the spectral template with the highest S/N, where the purple shaded region indicates orbital fits consistent within ΔS/N = S/N_peak − S/N_{velocity offset} = 1. This is compared against predictions by a GCM (red dashed line) for the velocity offset of iron lines in another typical UHJ, but with the slope scaled to the rotational velocity of WASP-189 b. This GCM included the effect of rotation and winds, and assumed no drag. Our alternative orbital fit is consistent with the literature, and its additional slope is consistent with 3D effects.