Choosing preferred theme for editing form elements

In older versions of Webform, the default theme for editing form components was the Admin theme of the current user. Now the edit page appears in the frontend theme, which is not suitable for me, because the columns are way too slim.

It would be handy to have a global option, where you can choose the preferred theme for:

* Editing form components
* Viewing submitted data
* other screens, that I am not aware of...