Same as in Fig. C.3, but for models with E = 3 × 10⁻⁴, Pr = 1, and N_ρ = 6. The model with Ra = 32 Ra_c requires a very high resolution and may be not fully resolved or relaxed. We checked this has no effect on the shape of the differential rotation; we nevertheless have to be cautious when considering the absolute value of the surface Nusselt. Note that panel (c) is similar to Fig. 6c but is added here for the sake of completeness and comparison.