Predictions for the tSZ power spectrum for a weak departure from self-similarity, factoring in additional mass-dependence for the scaling. The red solid line and the gray shaded regions have the same meaning as in earlier figures. The blue dashed line represents the tSZ power spectrum with α_z = −0.73 (Eq. (11)), as in Fig. 7. The green dotted line is given by a modified A10 pressure profile that has double mass dependence: f_gas ∝ M^0.2 for masses below M₅₀₀ = 10¹⁴h^-1M_⊙, and f_gas ∝ M^0.12 above this mass limit. Since this change alone is not enough to reach the SPT constraints, we need to introduce a redshift evolution, the result of which is shown by the magenta dash-dotted line.