Seeing (or literally not "seeing") an issue in X2a where I've added Plug-In automation, but when I go back to revisit the track, the color assignment (in the Automation menu) for the plug-in control is missing. This is not a problem in X1, but I don't know if this was an issue in X2 before the X2a patch.

A little more on this oddity. The Automation was there before the X2a patch. After the X2a patch, apparently, after resetting all the plug-ins (as instructed), it looks like all the automation assignments were orphaned. I went back in to re-add the same plug-in automation as before. I now have 2 separate automation lines for the same control, the Automation menu NOW shows the color assignment, but only for the NEW plug-In assignment. So, my session now shows "zombie" envelopes that cannot be re-accessed, although they don't seem to harm the audio.

Try opening lanes for them and deleting the ones you don't want.

They don't show up there, either. They're completely orphaned envelopes.