"dnf update" considered harmful

dnf has a similar feature, but it's generally believed that such features can never really catch *every* case where a software may need a restart. Just as an example, how do you handle the case where the plugins for some app are updated, and a running copy of the app won't be compatible with the new plugins, but none were loaded at the time the update transaction occurred? If the user then switches to the app window and tries to load a plugin things are going to go wrong, but it's very hard for such a mechanism to catch cases like that.