I don’t find a solution but I find some utils plugin:
Very usefull for the stock gestion. You can see your variation in table view on the admin side. But you can’t add variation quickly.
https://codecanyon.net/item/woocommerce-rapid-stock-manager-/10509723
An excel like product manager
https://fr.www.ads-software.com/plugins/smart-manager-for-wp-e-commerce/
