Tons of miles in Oregon on Autosteer and TACC very few issues with phantom braking.
But I think I’m still driving with the older radar based stack so that might be the difference.
Honestly, I think it's more to do with road conditions, and road layout. I'm also in the PacNW, and there are a few places where I can induce different behaviors 100% of the time...
One place, there is a road with a sweeping turn going down a hill. There is a large power transformer adjacent to the roadway in the middle of the curve... My Acura will slam on the brakes when I round that curve..... My Infiniti does not do this if I drive down that road, however, if I drive on the side street that T's with this road, right where the power transformer is... Half the time, my Infiniti will not only slam on the brakes, it will engage the seat belt pretensioners, as if it thinks a collision is imminent... My Vision Only Y does not phantom brake here at all... However, when I drive down this same road, my Vision Y will have a terrible time with the auto highbeams, as it gets fooled by a few overly reflective signs/reflectors, and hidden mercury vapor lights behind trees... However, my Infiniti does the same thing. The Infiniti is quicker to turn off the brights, but the Y is quicker to turn the brights back on...
There is another section of road, that is another sweeping curve, but this time has a light post right in the middle of the curve. Both my Acura and my Infiniti will momentarily slam the brakes, if I'm in the lane closest to the street light... My Vision Y does not brake in this section...
There is a section of freeway, on my commute... My Vision Y will report the speed limit as dropping from 60 to 25 for a 1/2 mile stretch of freeway, I have no idea why... There are no speed signs whatsover, and there is a burm on the left, and a freeway interchange on the right... I've taken that exit before, and the Y correctly says the speed limit is 60 throught the entire exit.. It only reports 25 if I stay on the freeway, for a 1/2 mile... My Infiniti, as well as Google, and Waze, all correctly report the speed limit as 60 in this section of freeway. I have no idea why my Y insists the speed limit is 25 on this section of freeway.
The only time so far in all my driving (which includes road trips for work every month), that I can get my Y to momentarily hit the brakes, is when I'm in the far right lane of a freeway, and there is a large vehicle merging. Sometimes if the other vehicle drives in lockstep with me in the merging lane, my Y will momentarily brake scrubbing about 10-15 mph off my speed. I can't get it to do it every time, but it seems to have to do with some combination with size of the vehicle, and how wide the lane/merge is, as I know the car has a tendency to drift to the right side, which may have something to do with this.. I haven't really had any problems with AP other than this, so I tend to just stay in the middle lane when using AP if I see/anticipate a car merging on the right.
I haven't tried to use AP on the windy roads near my house, but I use TACC all the time, and have never had my Y hit the brakes on me, which is contrary to my other cars. Those cars I don't even need to be using cruise for it to do that, as the conditions I listed earlier, I can get it to do with just the collision mitigation system.