When you connect, it's almost always going to be a different fe. If alt.binz doesn't show the welcome message in its logs, then some other program that does would be better for reporting frontend problems to UNS, and telling you which fe(s) to avoid. But look at the DNS for the SSL server:
Hostname: secure.usenetserver.com
IP Address: 208.49.82.92
IP Address: 208.49.82.185
IP Address: 208.49.82.218
The .92 address connects you to low-numbered fe's, and the other two connect you to high numbered fe's. If you discovered that a low-numbered fe was giving you a lot of 430's, you might be able to avoid that by using one or both of the other two IP addresses, instead of using 'secure.usenetserver.com'. One IP address could be used as primary, and another as a fill server.