The contribution containing the NAC vectors can be neglected since d α ν,ml is usually localized in space, and thus, it is expected to be negligible in comparison to f α ν,m , which is accumulated in time. This approximation might not be accurate if the trajectories spend a long time in a strong coupling region as the first term on the RHS of Eq. 14 becomes as important, or even larger, than the second term. Relaxing such an approximation in Eq. 14 requires to derive a new implementation for the calculation of the ct term in Eq. 13, which is beyond the scope of this work (but currently under investigation).