This is a useful plugin, but I feel that it has a fundamental problem.
I have existing CSS classes on particular widgets, and this plugin automatically overwrites those classes. As such, whenever the plugin is active, if I have existing classes on my widgets, these disappear and are replaced by the widget-logic classes. As such, any particular styling I have gets removed, purely by the activation of the plugin.
I don't think that a plugin should operate in this way. If the plugin needs to do so, it should add classes, not replace existing classes.
Other than that it is a useful plugin!