Bayesian-evidence comparison in our model grid. (a) Comparison between different planetary configurations and stellar-activity kernels, as well as for a potential presence of a sine component in the LTF (Sect. 4.2). Planetary configurations include planets with circular (C; e = 0) or Keplerian (K; e ≥ 0) orbits. For stellar activity, we utilised the MEP kernel and the ESP kernel with 2 or 3 harmonics. The model that we further elect for analysis assumed a sine in the LTF, three circular orbits and a MEP kernel (d4, red border; ln Z = −1114.4). We give the Bayesian factor ∆ ln Z of remaining models relative to model d4. (b) ∆ ln Z comparison of GP-free planet-free models that only model the LTF. We use this to break the tie between inclusion/exclusion of a sine in the LTF.