The relationship between ΔK for single S-type planets and the period ratio function ﹩{P}_{2}/{P}_{1}^{\frac{1}{3}}﹩. ΔK of systems above the green dashed line could exceed the ESPRESSO observation limit. Solid lines correspond to four different sets of continuous initial conditions with M_p = [0.01, 0.1, 1.0, 10.0] M_Jup, M_A = 1.0 M_⊙, M_B = 0.5 M_⊙, e₁ = 0.3, e₂ = 0.5, and the mutual inclination i_mut = 60°. The RV observation baseline T_obs is set to be 30 yr. Among the total 95 confirmed single S-type systems with a₂ < 100 au, the primary targets with potentially detected ΔK are marked with triangles, squares, and circles. The magnitude of ΔK for each system decreases sequentially from top to bottom and from left to right, as shown in the upper-right legend.