To redeem the Ehrenfest+R approach, one can modify the decay rate γ ′ R to absorb this additional term (the last term in Eq. B8), such that the following equality is explicitly enforced where the expression inside the logarithm in Eq. B10 has been replaced by the ratio of the magnitudes of the modified coefficients to the original coefficients (when explicitly using Eq. A27a and Eq. A27b). Eq. B11 is the correct modification regardless of whether a linear approximation of the exponential function is used when modifying the magnitudes of the coefficients (as has been done in most applications of the Ehrenfest+R method). This is validated numerically in Fig. where panels a and c are the results of the Ehrenfest+R method with the original γ R (and a linearization of the exponential when calculating the modified coefficient magnitudes) while panels b and d are the results when replacing γ R with γ ′ R from Eq. B11.