We're using the Zalando operator. We have our wals and base backups shipped to Azure Storage Blob. Not sure where this S3 only thing comes from. Can you exllain further?
The way I'm reading the comments here is 'AWS S3 as the only flavour of S3 that works', i.e. they're having issues backing up to to services like DigitalOcean Object Storage via S3, rather than S3 being the only backup protocol that's supported.
