I could imagine at most once being good for something like a ping or a heartbeat. Or even a "this is the current version of some piece of data". And if your con

I could imagine at most once being good for something like a ping or a heartbeat. Or even a "this is the current version of some piece of data". And if your consumers are prone to failing to ack and you don't want to gum up the queue with retries. But your point stands that it is certainly not what we want in the lions share of use cases. I guess that's why the default semantics are at least once. With at most once being a configurable option.