What happens if $process-message responds with an error? Is there any guidance you can provide on whether the system should retry sending? Or how the error should be handled? What does that mean for the workflow as a whole if the message fails to be retrieved? I stumbled onto this: "We are actively seeking input on whether additional guidance should be documented in this guide on FHIR-related errors (in addition to normal HTTP errors related to security, header and content type negotiation issues)." I do think it is important to provide guidance for handling errors\.