Thanks — - that what I suspected too, although I haven't tested it - I was hoping that the trigger would simply return an expression for the leaving device's id, rather than you have to check for a specific id in the trigger itself. Given that these ids cannot be known beforehand, I feel like it'll make for some clumsy events (however, my caveat is I haven't actually tested it yet).
I was looking through the plugin and noticed that DeviceIDLeft in the edittime is a number, but the returned value from the runtime is a string. Possibly an error? Or am I just misunderstanding it?
I'm still reading through the controller setup info, but returning c2 json messages is definitely the way to go.