According to the current SourceBans++ file, sb_main.sp
Comment out where the plugin issues game engine bans, e.g.:
1. Line 1635 - 1636
2. Line 2549 - 2551
3. Line 1539 - 1542
4. Line 2658
, you might also want to alter the plugin from using BanClient to use KickClient instead:
Something like for example
KickClient(target, "%t", "Banned Check Site", WebsiteAddress);
The stuff about caching the bans with game engine bans does something good, such as e.g. keeping people banned when you're having unreliable connectivity towards your SQL database(s).
If you are performing changes like the ones mentioned above (that you actually asked for), then your game server will send all the queries on each and every connect that players are doing towards your server.
While I'm banned on your server, you are opening up for the possibility that I can do reconnect spam towards your server, and then your game sever will spam your database with queries every individual time I'm trying to connect, which can potentially lead to "DoS" attack like consequences for your database server.
The game engine ban "cache" is actually doing good things for your servers / infrastructure!