what compatibility surface is prioritized first for SQS edge cases
Good question. I'm driving mostly off of my own use cases currently, so AWS SDK/CLI/Terraform compatibility. Response formats, codes, messages are best effort, there's a little work to be done there still. There's some gaps around request validation still too.
The idea is to build up a good suite of integration/regression tests as cases are identified by myself or the community (if there is one) through development.