In our previous study, we validated the performance of our NNP based on both energy/force errors relative to the DFT reference method as well as comparisons to an ab initio molecular dynamics (AIMD) trajectory, from which we obtained radial distribution functions, density profiles, and the vibrational density of states. Further validation of the model for this work is given in the SI, including comparison to AIMD velocity autocorrelation functions, comparison to experimental conductivity data in the bulk electrolyte, and assurance that the model uncertainty (quantified by the disagreement between the eight committee members) remains low throughout all simulations.