Select-based questions: Users can add new choice options even though item addition is disabled using the onCollectionItemAllowOperations event

[JaneSjs]

I want to disable the New Item option on a design surface. When setting the options.allowAdd to false within the creator.onCollectionItemAllowOperations event, the new item button disappears, however, the non-existing item persists.
View Demo

creator.onCollectionItemAllowOperations.add((sender, options) => {
      if(!!options.obj.choices) {
        options.allowAdd = false;
      }
    })

Workaround: it is possible to disable the new item using the survey.onShowingChoiceItem event (view an example). In the same manner, you would disable the special options (example).