The challenge with RDS in the past has always been getting the data easily and scriptable into an S3/etc bucket to start with. This might be a good enough solution.
Restore would be a pain, but at the point its needed the pain would be acceptable.
I can't speak specifically to this, but I will point out that you can just as easily run those 'rclone' commands in reverse, to move data from an rsync.net snapshot out to (insert cloud):
ssh user@rsync.net rclone .zfs/snapshot/1dayago/bucket s3:/some/bucketThe ssh access is not to Amazon, or S3 or RDS, etc. - you run the rclone command at rsync.net, over ssh:
ssh user@rsync.net rclone s3:/some/bucket local/rsync.net/dir