Before revision:  Furthermore, by using propensity bounds to couple processes, our approach allows simultaneous perturbation of many reaction rates in computing the sensitivities, which further improves the efficiency of the estimator.
After revision:  Furthermore, by using propensity bounds to couple processes, our approach allows simultaneous perturbation of many reaction rates simultaneously. Moreover, the data structure does not require to be updated frequently, hence improving the computational cost. This feature is especially useful when applied to large reaction networks.