I have not used jEPlus. My understanding is that it will generate a set of IDFs with the range of inputs that you desire for various user-selected variables. One could generate a similar set of CONTAM input (PRJ) files as well. Perhaps you could trick jEPlus into generating similar files for CONTAM PRJs as well (or, you can contact the NIST CONTAM developers (me) for a tool that will do this for you). You could then use Python to perform the "packaging" of IDF-ContamFMU input files and run your simulations. Again, I have a Python module that I have used to perform this process. Feel free to reach out directly if you are interested in pursuing this further.