All Products for WooCommerce Subscriptions

We are wanting to add the ‘allow backorder’ as a bulk ‘apply to all’ option in a products variations.
Specifically – in the edit product page, scroll down to the ‘product data’ and in the ‘variations’ tab. There is a ‘add variations’ drop-down menu that offers many options eg. changing prices or managing stock quantities. Within this drop-down we would like the option to allow backorders. If you open any of the product variations the option to ‘allow backorder?’ can be selected as ‘allow’, however we are unable to change all of the variants in bulk.

I have also tried selecting and editing multiple products in the ‘all products’ page. Within here there is the option to ‘allow backorder’ for the products selected. However, after saving, I have gone in to check the products and not changes have been made.