There only appears to be an option for downloading backups when they are manually generated. Only restoration is possible with automatic daily backups. I would suggest also adding the download facility to automatic backups.
Today, one of our sites had some files accidentally removed during its development, but as other updates had also been made, it was not ideal for the site to be restored to a previous point as updates would need to be repeated. The removed files could have been retrieved and re-inserted into the site quickly by ourselves if the automatic backup from the evening before was downloadable, but unfortunately we had to contact support and resolve it this way which takes up time for both the customer and resources from support.
Having auto-generated backups which are downloadable not only simplifies the packaging up of sites where a manual backup hasn't been made, but also helps in situations where previous backup files are needed WITHOUT the restoration of a website to a previous point.
Thanks
Drew