Jim,
Articulations are another animal. I am strictly talking about key switches for pattern based VSTi's for programming pattern changes and shots/holds

When you create a Chord Track through Preferences>Output Chords, you are given a choice of range. The easiest way, I think it can be done is to have a "second" range reserved for key switches, that will remain in place, no matter what you do with re-generation or chord changes, to be only edited manually through piano roll, while the "active" range will rewrite block chords when chord or bar changes are introduced.

There are couple of workarounds, mainly what Musocity mentioned, but that would require extra steps and re-routings. What I proposed will be a single track that includes both, a chord changes and key switches. Universal file for BIAB or any DAW. I have to think about this for some time before heading to wishlist.