In reply to Ben Ditto.

Thanks. That's exactly what I'm suggesting. The Classic Editor plugin already provides a couple of options so there should be no issue in adding an extra one to select the editor type for the Widgets screen. I don't think the plugin would need renaming either. You're still effectively using the Classic Editor when using the "old" widgets screen. It would be a much better experience for the existing 5M+ users who are already using this plugin, to not have to now install yet another plugin to also remove Gutenberg from the Widgets screen.