Setting minimal TLS version to 1.2 improves security by ensuring your SQL Managed Instance can only be accessed from clients using TLS 1.2. Using versions of TLS less than 1.2 is not recommended since they have well documented security vulnerabilities.
Ensure security controls for remote access to server include the following:
(a) restrict access to only hardened and locked down end-point devices;
(b) use secure tunnels such as TLS and VPN IPSec;
(c) deploy ‘gateway’ server with adequate perimeter defences and protection such as firewall, IPS and antivirus; and
(d) close relevant ports immediately upon expiry of remote access.