Give customers a useful error message if the FedEx API fails.
When the API does not return rates, such as with the error below, customers should see an error like "FedEx wasn't able to provide rates. Please wait a moment and refresh the page to try again."
Furthermore, being able to change the fallback message in the UI or at least by a filter would be really useful.
Being able to disable the shipping method in the case that the API fails would be a great part of the feature.
Error we are getting intermittently, confusing customers:
[HIGHESTSEVERITY] => FAILURE
[MESSAGE] => RATING IS TEMPORARLY UNAVAILABLE, PLEASE TRY AGAIN LATER.