Firstly, this is not a complaint. I'm wondering if their is some way to help deal with the added Halloween mobs building up in our grinder's. This issue has made spawner based grinding inefficient. I'm aware of setting the mob spawning off for other areas of claimed chunks, so that's easily dealt with.
To be honest, I would just wait until the event it over. It's such a short event and making adjustments to grinders to make them efficient with the Halloween mobs would pretty much be a pain in the behind for the small amount of time left. ..just my opinion though. ^_^
Unfonretly its nothing that can be done unless we remove the plugin. The event ends in 5 days anyway. Sorry nothing can be done sooner.