wc vendors pro new add a custom text field for message on product page

functions.php

function add_custom_info_field() {
    WCVendors_Pro_Form_Helper::input ( array( 
					'id' 		=> 'custom_info_message', 
			 		'placeholder'	 	=> __( 'add a message ...'),  
			 		'value' 	=> $value 
				)
			);  

}
add_action( 'woocommerce_after_add_to_cart_button', 'add_custom_info_field' );

/* Saves field data */
function save_add_custom_info_field( $cart_item_data, $product_id ) {
    if( isset( $_REQUEST['custom_info_message'] ) ) {
        $cart_item_data[ 'custom_info_message' ] = $_REQUEST['custom_info_message'];
        /* below statement make sure every add to cart action as unique line item */
        $cart_item_data['unique_key'] = md5( microtime().rand() );
    }
    return $cart_item_data;
}
add_action( 'woocommerce_add_cart_item_data', 'save_add_custom_info_field', 10, 2 );

/* Renders field entry on cart and checkout */
function render_mssg_meta_on_cart_and_checkout( $cart_data, $cart_item = null ) {
    $custom_items = array();
    if( !empty( $cart_data ) ) {
        $custom_items = $cart_data;
    }
    if( isset( $cart_item['custom_info_message'] ) ) {
        $custom_items[] = array( "name" => 'Custom Info or Message', "value" => $cart_item['custom_info_message'] );
    }
    return $custom_items;
}
add_filter( 'woocommerce_get_item_data', 'render_mssg_meta_on_cart_and_checkout', 10, 2 );

/* Renders field info onto orders pages and emails */
function custom_info_order_meta_handler( $item_id, $values, $cart_item_key ) {
    if( isset( $values['custom_info_message'] ) ) {
        wc_add_order_item_meta( $item_id, "Customer Message", $values['custom_info_message'] );
    }
}
add_action( 'woocommerce_add_order_item_meta', 'custom_info_order_meta_handler', 1, 3 );

This breaks the "Sold Individually" function. When Sold Individually is checked customers can add more than 1 product to their carts if this function in their functions.php

Could you update this function to work with the most updated version of pro please? I really need to use this with sold individually option.