Drupal Commerce 2 - Create Simple Stock with Custom Module and ECA
About 2 years ago, I tried Drupal Commerce 2 and the module itself doesn't have comment system that a shop owner can use to make a note to let customer know and customer can also check that note in order information page. Shop owner can decided to send notification to customer though an Email, if needed. At that time, I decided to use Drupal Core Comment together with Rules module to create a comment form and use to communicate with customers.