Under your account manager, uncheck "accept hub bans", and check "enforce bans".
This leaves your ban list free for your local bans and bans from sites such as PsB.
When a client connects to your server, their GUID is checked against the MBI. If they're on the MBI, they're kicked and banned from your server.
So, a shorter, more efficient ban list, without compromise. Also, if you do this, there's no uploading ban lists via ftp :)