No, that would be postfix (SMTP).
Dovecot is only POP3/IMAP.
According to this documentation, it should be already disabled. However you are limiting the reachability of your mailserver if you restrict it, because there are many misconfigured mail servers out there.
The configuration is enforced to TLS 1.2 if you require TLS for certain domains. If TLS is not enforced for a certain domain, it will accept any TLS version, and even falls back to unencrypted.
I wouldn’t change those settings