Thanks for all the replies.
It's looks like this will turn out to be a combination of faults.
A. High speed driving. Yes, we do run 80-85 here on our freeways.
B. Very slightly out of alignment.
C. lower quality OEM tires,
D.Maybe even our Michigan cold climate (as Mike T points to low mileage Canadian tires).
The alignment was done by the Toyota dealer from the numbers fed them by Bloomfield Smart. So no conflict there. We go by the door tag on TP and watch it closely. A2Jack.