> I've heard legends that somehow the OrdinaryCallingFormat doesn't work in other regions

This was the calling format for anything using the connection object established in [wal_e.operator.s3_operator:47](https://github.com/wal-e/wal-e/blob/da34c0cd5fedc79ad634cc4fa08c232e04e019ce/wal_e/operator/s3_operator.py#L47) before #3 was merged in.  `worker.s3_worker` does not use the same connection code path so I imagine it was defaulting to OrdinaryCallingFormat since nobody had reported any problems with it prior to the customizations from #3.

> but a simple "has caps?" is easier to (not) test and delivers 100% accuracy

I had considered that but then realized that the fallback behavior is (currently) the same for all error cases - that is, we default to the standard region.  It seemed redundant to test for two cases with the same exception handling.