Sorry for the late reply, just saw your comment. I think what you're describing is training a model and then using feature importance. This is also a valid meth

Sorry for the late reply, just saw your comment. I think what you're describing is training a model and then using feature importance. This is also a valid method for calculating sensitivities and it's used if the function from inputs to outputs is unknown. However, in our case, this function is known so there's no need to train a predictive model.