This seems wrong, since you can't push transactionally + consistently in S3.
They address this directly in their section on concurrent writes: https://github.com/awslabs/git-remote-s3?tab=readme-ov-file#...
And in their design: https://github.com/awslabs/git-remote-s3?tab=readme-ov-file#...
But it seems like this is just the wrong tool for the job (hosting git repos).