Change the order from additional checkout fields in WooCommerce checkout manager

Solution:

WooCommerce checkout manager plugin doesn’t allow to reorder additional fields and it save that data in some of his option settings.

So the way is to alter the plugin settings just once.

To run the following code, just browse any page of your web site.
You will run it just once and then remove it.

The code:

function wccs_change_fields_order(){
    $wccs_settings = get_option( 'wccs_settings' );

    // Get the array of additional fields
    $additional_fields = $wccs_settings['buttons'];

    // SETTINGS: Here set your 2 product attribute Names
    $format    = 'Format';
    $rp_carton = 'Rolls per Carton';

    // FIRST Loop Get the array key for 'Rolls per Carton' field label
    foreach( $additional_fields as $key => $field ){
        if( $field['label'] == $rp_carton )
            $key_rp_carton = $key;
    }

    // Save 'Rolls per Carton' data field in a variable
    $field_rp_carton = $additional_fields[$key_rp_carton];

    // Remove 'Rolls per Carton' data field from the fields array
    unset($additional_fields[$key_rp_carton]);

    // Initializing variables
    $new_additional_fields = array();
    $sorting_index = 1;

    // SECOND Loop reordering fields
    foreach( $additional_fields as $key => $field ){
        // Update "order" argument
        $field['order'] = $sorting_index;

        // Add the current field to a new array
        $new_additional_fields[] = $field;

        $sorting_index++; // Increment sorting index

        // When we reach 'Format' data field
        if( $field['label'] == $format ){
            // Set a new position to 'Rolls per Carton' attribute
            $field_rp_carton['order'] = $sorting_index;

            // Add 'Rolls per Carton' field data in the new array
            $new_additional_fields[] = $field_rp_carton;

            $sorting_index++; // Increment sorting index
        }
    }
    // Set back the reordered additional fields in the main array
    $wccs_settings['buttons'] = $new_additional_fields;

    // Update the new changed options (Save)
    update_option( 'wccs_settings', $wccs_settings, 'yes' );
}

wccs_change_fields_order();

Code goes in function.php file of your active child theme (or active theme). Tested and works.