I haven't had chance to try this yet but I noticed this in the CLI readme file:
Ban a user from logging into the VPN or Web server
(doesn't affect a user who is already logged in -- for this,
use DisconnectUser below):
./sacli --user <USER> --key prop_deny --value true UserPropPut
Re-admit a user who was previously banned:
./sacli --user <USER> --key prop_deny --value false UserPropPut
I'm wondering if that would work to unlock an account immediately.
Will give that a go next time someone is locked out and let you know.