Your suppositions along these lines were all incorrect, I’m sorry to say. As we’ve said, plugins can override templates, but controllers are selected by changing your routing. There are various ways to do what you’re looking for, but even just describing the basics of different options is a lengthy discussion. Here is a topic I had a while ago about this sort of thing, maybe it will help. But plugins aren’t the only way to go; in addition to using plugins, my app has bits of functionality that are enabled or disabled through config files or through administrative setting pages.