* Fix - Use method_exists to accommodate for backwards compatibility with older WC versions. * Tweak - WC 5.1 compatibility. * Tweak - WP 5.7 compatibility.
* Add - Menu item to the new WC Navigation. * Tweak - WC 5.0 compatibility. * Tweak - WP 5.6 compatibility.
* Fix - Use core's status functions instead of hardcoding for validations.