So I was in a zoom meeting with a bunch of Arduino Engineers today and someone mentioned that the Portenta Vision Shield microphone should work with the PDM example that comes with the Nano 33 Ble Sense. So I tried it and it does. The next obvious step is to try a sound impulse. Which also worked.
So that is my first program using Arduino C, Edge Impulse but running on the new Portenta Vision Shield.
P.S. For sound deployment, there is no OpenMV. Is that now possible? I believe OpenMV has working sound examples in micro-python now.