I went and played with this some more. One interesting note is that one of the cabinet setups this track switches too did not even exist until last weekend! I have not saved the file, so that was just "odd."
Basically, I deleted the effects, copied the track to a new project, reinserted GR5 and the issue is back. I disabled both track read automation, as well as globally, and it continues to do this, so I am now incredibly baffled as to what exactly this is. The events list is blank, and disabling read automations doesn't stop it (I also disabled all the plug-in parameters from SONAR).
NI sent me a response to try to first clear the controller, which I did, but to no effect. They also suggested that the triggering data is in the track itself, which is a pretty solid assumption after copying this to a new project.
I will have to play with this some more to see if I can resolve it. I am going to redo this particular track anyway, but am more concerned for the "what if" event that I do this on something "final." One work around is that other plug-ins are not triggered by these, even GR 4 (go figure). It would also help to know how I inserted these mysterious automations in the first place, so that I do not do it again (this particular track was first recorded 13 years ago).
Yikes.... Another massive concern with this I just verified :( If a project is NOT bundled... the audio track "master" is modified, since it is really only one file that is pointed to by SONAR. I just opened an X1d version of that file and inserted GR5 on that same audio track... and the automation issue is identical... so it is embedded into that audio track. Definitely a point for bundled backups!