You can use filter dlxplugins/ajaxify/comments/options/pre_output
to filter the options returned by the plugin.
The filter accepts 3 arguments:
$options
: (array) Optioons array containing the labels.
$post_id
: (int) Post ID of the comment being posted to.
$post_type
: (string) Post type of the comment being posted to.
Here is an example of changing the labels for WooCommerce reviews: