Left: RM time series for WASP-118 and WASP-166 after subtraction of the mean RV. Green points indicate the out-of-transit measurements used to estimate the reference RV trend (solid line), while gray points are affected by the RM anomaly and are excluded from the fit. Right: leave-one-star-out predictions for the same systems. The panels compare the observed RVs (blue), the ML-predicted reference RV trend (orange), and the reference RV trend derived from the out-of-transit fit (green).