Evolution of key quantities relevant for the binary orbit after the initial envelope spin-up and adjustment. Panel a: moving average of the specific angular momentum transfer ⟨j⟩_P (Eq. (32)) for models A, B, C, and D. The black dashed line indicates the critical specific angular momentum transfer j_crit = 3/8. Panel b: moving average of the gravitational torque for simulation runs A and A′. The black dashed line indicates . Panel c: moving average of the mass accretion rate through the inner boundary ⟨Ṁ⟩_P. Panel d: envelope mass in our numerical domain M_env(r ≤ 10). Panel e: moving average of the orbital separation evolution timescale .