I have been getting the odd noise at a very narrow power level, either + or -. It can be duplicated by feathering the accelerator, and yes the cruise can make it happen when the terrain changes subtly. It seems to be evolving. I first heard it at around 20 KW draw a few months ago. Now it's at a very low draw, like 3 KW. The pitch is speed related.
Also I'm getting the click/clunk at very low speeds (5 MPH) when switching between accelerate and decelerate.
I mentioned these to service, but they say they haven't heard any unusual noises, and couldn't duplicate the click/clunk.
I think I will have to get one of them in my car while I have it make the noises. Hammering a broken washer or bad bearing will cause damage to other parts over time.