Evolution of a stellar binary (black) with four (noninteracting) CBPs in a coplanar configuration. The masses of the inner stellar binary are m₁ = 0.56M_⊙ and m₂ = 0.46M_⊙. The initial semimajor axis and eccentricity of the inner binary are a_b,0 = 0.09 au and e_b,0 = 0.8. The outer orbits, ordered by increasing distance, have initial semimajor axes a_p = 0.72 au, 1.24 au, 2.13 au, and 2.81 au. All four begin with eccentricity e_p,0 = 0.001. The longitudes of pericenter for both the binary and the planetary orbits are initialized to ϖ_b,0 = ϖ_p,0 = 0. Each binary–planet system is evolved independently (i.e., without planet–planet interactions) by integrating the SA secular equations (Equations (1)–(3)), where the TD is included in the binary evolution (top and middle panels). The bottom panel shows the corresponding apsidal precession rates computed from Equations (5) and (8).