This is great! I really wished this existed a few years ago at my previous company. We needed this exactly. A straightforward way to get ftp files into blob. Is it possible to cname/whitelabel the domain of the ftp address?
But for SFTP, and FTP (insecure, not that you'd want to) CNAME works fine.
We do do seperate SSL certs but it is only for bigger customers that we host dedicated instances on their behalf.