Can Simultaneous-Use be used with EAP-TLS?

[Jason Wittlin-Cohen]

I am using EAP-TLS for authentication so I have no use for a backend db
to check username/password credentials. However, I would still like to
prevent simultaneous logins with the same certificate. Is this possible
without having an sql database? I have "Simultaneous-Users := 1" set in
the "users" configuration file but it doesn't seem to do anything.

Clients are being checked against this line in "users"

DEFAULT Simultaneous-Use :=1