By looking at many examples it seems like the "response" method runs some other method or create a zwave event. However I have to believe there some other significance else it wouldn't exist. I found it in the Habitat Documentation, however it was in the TBD (to be documented) list.
I never use it since as far as I can tell, there isn't anything you can do with it that you can't already do via either the "typical" method for sending a Z-Wave commands--either the return value of a Hubitat command or "manually" with sendHubAction(), as you've seen in other threads. I guess maybe it saves a bit of typing compared to creating a HubAction manually if you're doing the latter? (And really, you still have to do something with it either way--calling it doesn't send anything on its own.) I'd love to hear what people actually like to use this for. It's rare in Hubitat drivers from what I've seen, but I suppose I haven't seen everything.
I had seen the Smartthings text (usually the 2nd place I look), but even with their I was unable to determine what benefit it offered. However I've found the Smartthings documentation assumes I'm more advance that I am