Why did you remove the four ridges on the outside of the AeroPress Original plunger?Updated 24 days ago

We removed the ridges from the AeroPress Original plunger because they were scratching the inside of the chamber and had no function. We initially put the ridges on the plunger because we thought they would provide needed additional strength. That was not the case and to our surprise they were a source of scratching of the inside of the chamber.