Top: local RVs as a function of phase (in black), over-plotted with the various model fits for the velocity contributions behind HAT-P-30 b along the transit chord. Bottom: residuals between the measured local RVs and the aforementioned model fits, with a dotted line at 0 km s⁻¹ to guide the eye. We note the DR fit without additional priors is a poor fit due to the bi-modal distributions in the fitted parameters, see main text and Appendix B for details.