Plugin not following WooCommerce developer recommendations for CRUD operations

Hello!

first of all thanks for your work in this plugin.

I realized that actually the plugin code is not following the WooCommerce recomendations regarding CRUD operations: https://docs.woocommerce.com/document/developing-using-woocommerce-crud-objects/

To fix it regarding Order objects it can be done by:

--- a/woocommerce-product-price-based-on-countries/includes/class-wcpbc-frontend-pricing.php
+++ b/woocommerce-product-price-based-on-countries/includes/class-wcpbc-frontend-pricing.php
@@ -491,7 +491,8 @@ class WCPBC_Frontend_Pricing {
         * @param array $data Order metadata.
         */
        public static function update_order_meta( $order_id, $data ) {
-               update_post_meta( $order_id, '_wcpbc_base_exchange_rate', wcpbc_the_zone()->get_base_currency_amount( 1 ) );
-               update_post_meta( $order_id, '_wcpbc_pricing_zone', wcpbc_the_zone()->get_data() );
+               $order = wc_get_order( $order_id );
+               $order->update_meta_data( '_wcpbc_base_exchange_rate', wcpbc_the_zone()->get_base_currency_amount( 1 ) );
+               $order->update_meta_data( '_wcpbc_pricing_zone', wcpbc_the_zone()->get_data() );
        }
 }
diff --git a/woocommerce-product-price-based-on-countries/includes/class-wcpbc-pricing-zones.php b/woocommerce-product-price-based-on-countries/includes/class-wcpbc-pricing-zones.php
index fe7aeeb7..456508c7 100644
--- a/woocommerce-product-price-based-on-countries/includes/class-wcpbc-pricing-zones.php
+++ b/woocommerce-product-price-based-on-countries/includes/class-wcpbc-pricing-zones.php
@@ -233,14 +233,15 @@ class WCPBC_Pricing_Zones {
                }
 
                if ( $order_id ) {
-                       $data = get_post_meta( $order_id, '_wcpbc_pricing_zone', true );
+                       $order = wc_get_order( $order_id );
+                       $data = $order->get_meta( '_wcpbc_pricing_zone', true );
 
                        if ( $data ) {
                                $zone = self::get_zone( $data );
                        } else {
                                // Find zone by order country.
                                $based_on = get_option( 'wc_price_based_country_based_on', 'billing' );
-                               $country  = get_post_meta( $order_id, '_' . $based_on . '_country', true );
+                               $country  = $order->get_meta( '_' . $based_on . '_country', true );
                                $zone     = self::get_zone_by_country( $country );
                        }
                }

Would be awesome to see it introduced in the next release. If there is another better way to contribute code improvements I will be happy to use it.

Thanks so much.