Anti-Exploit Measures for Caravan (Can I have it?)

[Felis]

If you have someone who want just be a leecher, do nothing. Maybe he go away after he get gysal green instead of seals the third time.

Other option would be a forced party. Everyone who participate in the caravan would put automatically in a party. If someone leave the party or is kicked out (if the majority want to kick him), he don't participate anymore.