On Thu, 6 Jul 2017 05:46:09 -0700 (PDT), wrote:

have you had the tires rotated (changed position on the car)

I drive about 8K miles a year and it has been about 4K miles so I had my
teenage son rotate them for me. So now the edge "feathered" tires are on
the rear.

But rotation or lack of it isn't the reason why the tires are feathered nor
is it the solution.

So far it seems that either the daily 5 miles each way of steep twisty
hills is the problem (which can't be solved) or there may be an alignment
issue with both front tires.

They are evenly "feathered" on the outside edge, so it's not just one
wheel.