I thought we shot this idea down a little while ago. I believe the request was for an "auto-cast" mod though, rotation mods are just one or two steps from being within the realm of the ever present EULA compromising "botting" program, and this is why Blizzard has
yet to stop the use of these types of mods.
I understand where you are coming from, but I didn't think there was a way to dynamically "sense" the proc for debuff or buff, theoretically it'd be possible to watch for the text on proc that occurs within triggering mechanics, but even that is borderline automation.
I'm probably wrong and my mind is off a bit, someone with more knowledge/focus might be able to point out my incorrectness. Honestly I just can't remember.
/Edit: found the post
here.