Caching – function.php ignored?

First and foremost, I very much like your plugin.
Like others, I cannot switch off caching (which takes up a lot of space and might also create legal problems). I tried overriding the setting by including this in my theme’s function.php

add_filter('content_cards_options', function($data) {

     $data['cache_images'] = false;

    return $data;
}); 

but this is ignored, too. Changing the default in contentcards.php seems to work but is obviously not ideal.