Our study begins with a case study on PIM-PI-8 membranes, establishing a detailed protocol for the DCVMD setup, emphasizing the procedures required to achieve steady state conditions. Sensitivity analyses indicate a strong dependence on independent configurations and individual trajectories, along with a size effect of the membrane. Consequently, we emphasize that the data need to be averaged over multiple independent polymer matrix configurations with individual trajectories to ensure statistical robustness. Key properties examined in this study include permeability, perm-selectivity, density profile, solubility, and diffusivity.