Example dynamical history of GJ 436 b via ZLK migration with an outer companion of mass m_c = 0.24 M_Jup on an orbit with a_c = 28 au, e_c = 0.62, and I_mut,i = 85°. GJ 436 b was initialized with a_b,i = 1 au. The panels show the evolution of 1 − e (top left), mutual inclination I (bottom left), semimajor axis a and periapse distance a(1 − e) (top right), and spin–orbit angle Ψ_Ab (bottom right). The present-day state captures GJ 436 b during its ongoing tidal evolution before reaching the final semimajor axis plateau, as the planet has not yet achieved complete tidal circularization given its observed residual eccentricity. The red points indicate the present-day values for each parameter with measurement uncertainties. The time axis is truncated between 1 and 7 Gyr, indicated by break marks. The inset in the top left panel compares the octupole-level (black solid line) vs. quadrupole-level (red dashed line) approximation.