Improper use of render arrays

The way this module implements Drupal's render arrays means that it is very difficult to theme. For example, I need to add a CSS class or two and remove some classes from various elements that Quicktabs provides. Unfortunately this simply isn't possible cleanly, because Quicktabs is doing things such as:

'#prefix' => '<div id="quicktabs-container-' . $qt_name .'" class="quicktabs_main quicktabs-style-' . drupal_html_class($settings['style']) .'">',

Hardcoding all this HTML into a #prefix is not how render arrays should really be used, as it gives the theme layer absolutely no ability to modify either the tag (in this case a DIV) or the CSS ID or class (other than completely overriding the various theme functions, or PHP string replace-ing).

Another example:

'class' => 'quicktabs-wrapper quicktabs-style-' . drupal_html_class($settings['style']),

Sending classes into a render array would be much better done as follows:

'class' => array(
    'clearfix', 'my-class', 'another-class',
),

Doing so would thus allow themers to modify these classes cleanly.