Drop targets are registered on a per-dropper basis. Each dropper knows how to drop items to a given number of relevant drop targets. You can add your own and register to individual dropper types by using the drop handler’s registerDropTargetType. I’m unsure how clean this API is, which is why it’s manually implemented in each drop handler, but I’d ask that you stick with it for now, and let me know of any feedback you have via the Discord.