Optimising the S/N of the ΔCCFs at Δv = 0 km⁻¹ in the planet rest frame, for all orders and all the nights combined, optimised for cases 1 and 2 (top panel) and for cases 3 and 4 (bottom panel). More SYSREM iterations improves the model recovery when rotational broadening is not included, indicating that SYSREM is likely removing the wings of broadened signals and thus should be used with less iterations.