Unless your server runs an ancient Operating System (CentOS 5, looking at you), your server is compatible with and uses SNI.
What is SNI?
SNI is the technology that allows services to serve multiple SSL certificates on a single IP address. It enables you to install an SSL for domain1.tld and another SSL for domain2.tld, and visit both with a secure protocol.
Does FTP use SNI?
ProFTPD and PureFTPD on cPanel & WHM servers do not currently support SNI.