What do the different modes mean?

[SawkeeReemo]

I'm trying to cleanup my Homebridge installation, and I've decided to set your Wemo plugin up again from scratch. But I'm noticing if I set the mode to auto, it lists all my devices twice. So I thought I'd try the other modes, but I don't know what they mean. When I set it to manual, there's no place for me to manually enter anything in the UI config. So I'm assuming I have to do that in the JSON, but I don't see how you're supposed to configure it.

And what does "configured devices" mean? Isn't that what we're trying to do with this plugin? Would really love a simple explanation as to what these modes are actually doing, please.