Cool! I haven't tried ABM yet, but I'm glad to hear they're compatible
At first I chose the world db folder because I was following the example plugins, but then I realized there's another good reason to do so. Since the plugin works in singleplayer too, each singleplayer world has it's own chicken coops db, Whereas if it was one universal chicken coop db, every chicken coop from every singleplayer world the player has would get loaded no matter what world was chosen to load up, you'd find chicken coops in some interesting places I bet that way.
Can you think of any potential problems of putting the db in the world folder? I haven't thought of any, but I'd like to know your ideas.
I do not see any problem with the db being where it is. I have just seen it put in the plugin folders and if it needed to separate worlds they named the db after the world but I think your solution is the easer 1. Store the db in the world db folder