A simple metric on confidence interval could do the trick. As the model grows larger, it is getting more difficult to understand what is going on, but that does

A simple metric on confidence interval could do the trick. As the model grows larger, it is getting more difficult to understand what is going on, but that doesn't mean that it needs to be a total black box. At least let it throw some proxy metrics. In due course, will learn to interpret those metrics and adjust our internal trust model.