In order to avoid that internationalizable text fields take up too much space in the admin UI and because most institutions will only be offering the T&C in 1 language, I'd prefer a solution where there is a dropdown list where you can select a language (default language would be the default) and 1 visible textarea at a time that shows the text for the selected language. We probably still want the textareas for all other languages to be present (but hidden), to make serialisation more straightforward.