Hello,
Thanks for the feedback!
Unfortunately ACF or ACF Extended don’t have any specific feature related to Woocommerce. So you won’t find specific “Woocommerce” functionalities.
However, as far as I remember, the Woocommerce Product Variations feature is just a native WP Taxonomy. So you should be able to display an ACF field in there using the ACF Field Group location “Taxonomy = Product Variations”.
Note that Woocommerce do some very custom stuff in their Product Variations logic, so you’ll probably have to use Woocommerce hooks in order to retrieve/process your field values in the checkout logic.
Hope it helps!
Have a nice day!
Regards.