For me, the most useful mode of operation is to use SoftEther's HTTPS interface on TCP port 443 since it will cut through the most restrictive firewalls. However, using ssllabs.com server testing tools, I found that SoftEther uses insecure methods. Specifically, the RC4 cipher and TLS modes below TLS1.2, i.e., TLS1.0 and TLS1.1.
In the next SoftEther release, please eliminate the use of RC4, TLS1.0 and TLS1.1.