welcome to the forum, thanks for posting,
have you seen the bucket policy in the rclone docs?
it is basically the same as what you posted, but is more locked down, uses less permissions.
https://rclone.org/s3/#s3-permissions
if you want to know more about advanced, locked user/bucket polices, check out my post.
https://forum.rclone.org/t/unable-to-upload-file-to-bucket-with-put-only-iam-policy/42636/6?u=asdffdsa