They are still pretty limited compared to what's in the enterprise version, but it's not right to say basic backups are closed source and have never been there.
> My current database is in a private subnet, it would be unfortunate to have to open it up to the world to take advantage of this.
Agreed, this is a big current limitation. As mentioned in the blog post, though, we'll be adding support for connecting into private networks via our other networking products (Cloudflare Tunnel and Magic WAN).
They are still pretty limited compared to what's in the enterprise version, but it's not right to say basic backups are closed source and have never been there.