Disable profile copy checkbox on admin order edit page

Actually, disabling the profile copying would have to be done from Commerce shipping itself, since it is the one adding that checkbox, via the following code:

/**
 * Implements hook_commerce_inline_form_PLUGIN_ID_alter().
 */
function commerce_shipping_commerce_inline_form_customer_profile_alter(array &$inline_form, FormStateInterface $form_state, array &$complete_form) {
  // Attach the "Billing same as shipping" element.
  $profile_field_copy = \Drupal::service('commerce_shipping.profile_field_copy');
  if ($profile_field_copy->supportsForm($inline_form, $form_state)) {
    $profile_field_copy->alterForm($inline_form, $form_state);
  }
}

We'd probably need to alter the supportsForm() method to check if the form is the order edit form.

Ahh, thanks! I didn't look too deeply into where the checkbox came from. I'm going to relate this one to another shipping UX improvement I proposed for the order edit form, too.