arf_form_fields_outside

add_filter('arf_form_fields_outside', 'your_function', 10, 2);

function your_function($field_json, $input_style){



    foreach ($field_json->field_data as $key => $value) {                           

        foreach ($value as $data_key => $data_value) {

            if($data_key == 'KEY'){

               $field_json->field_data->$key->$data_key = DEFAULT VALUE;

            }

        }

    }



    return $field_json;



}