I think rate increasing is useless, Farmer still farmer. They will farm always until the event is done. The best way in my opinion is make the spawn spot random around the map, not at the same spot. Let's the old player, farmer hunting by themself, Not just HK and PK at the same spot. And maybe random the time to spawn not set the CD time for every 3hrs atm.

Dev can do it and any players that can dev game or coding know that how to do so. Nothing hard to do.

They just don't mind it, I hope next time they can solve these problems.