I find that the specifics on how to do it isn't documented very well. They do have information in the Help that is somewhat - mostly helpful. Usually I just look at the native stuff and see what they did in there and then mimic it. However, for the ModelPluginConfiguration callback they don't have an example in there. So what I would do is look in the Plugin and see what they are doing with the data in that callback. It would help me understand what each of the parameters mean. Then when I overrode it I could kind of mimic what they are doing but with my own twist.
Sorry I'm not more helpful with this.
