I don't doubt your personal experience, but the general consensus runs toward highly inflated and hyper inflated tires wearing faster at the center. Now, some tires have a layer under the tread that flattens out the tire even at higher pressure - not sure if ours do or not....
This is what happens when technology advances... the old rules of thumb become old wives tales, which spoil into snake oil very quickly.
ALL our tires have " a layer under the tread that flattens out the tire even at higher pressure." That wasn't always true...
Once upon a time, all tires were "bias ply" tires. the tire carcass was constructed around a pair of skewed sheets of rubber bonded to fabric. The sheets were oriented so the fabric weave crossed at a specific angle to give both strength for pressure containment and flexibility. This is still a common method of making heavy-duty tires, such as agriculture and aviation. Major drawbacks are poor cornering traction and poor tread life. These are very sensitive to inflation pressure, since they are just a balloon.
In my youth, this began to change. There was an odd French company with a roly-poly mascot named Bibendum that made their tires differently, and always included a circumferential ply or "belt." Other tire makes studied Michelin's approach, shying away from the radical radial construction, but picking up on their tread belts.
The result was the bias-belted tire, a bias ply carcass with several steel or fabric belts under the tread area of the tire. These belts stiffened the tread area, making it harder to pull up the edge of the tread, as bias ply did, but this came at a cost. When pushed hard, that entire belted tread area would come up, and traction would disappear. These were hard tires to drive at the limit. At the same time, the belt stabilized the tread when rolling in a straight line, and the tread life improvement resulted in quick adoption of belted tire technology. But belts were not a cure, rather a bandage to stop the bleeding. It took some Arabs shutting off our oil to start the next revolution.
You see, Michelin had it right. By orienting the carcass plys in the same direction, not skewed, and perpendicular to the tread, Michelin had developed a radial tire that liked to bend. By stiffening the tread with belts, they created a tread area that was decoupled from the sidewalls, allowing a single tire to be soft in the sidewalls, for smooth ride, but stiff in the tread, for performance. They cost more to make, required different manufacturing equipment, and they were harsh on the road, when installed on cars optimized for bias ply. However, their rolling resistance, and so fuel consumption was much lower than even belted bias ply, and CAFE had just come along...
As a result, VERY FEW OF YOU have ever owned a car with bias ply tires. I had them on my first car, a 1970 Maverick, moving up to belted bias ply when the first one dies at 20K miles. My second car, and all since, have radials. In contrast, NASCAR is still transitioning from bias ply to radial tires, for some very good reasons.
Anyone remember the Firestone 500 debacle? Per the web site linked above, it was a result of making radials on the cheap, using bias-ply equipment.
So, no, inflating a tire above the door placard will not hurt tire life, but it remains foolish to inflate above the sidewall rating for any period of time, regardless.