At a point, I noticed that my primers were not seating as well as when the press was new.

The problem was tracked to the bottom of the primer punch creating an indent where it contacts the frame. This in turn reduces the travel of the primer punch, increasing the number of primers not being seated properly.

A quick fix is a steel washer epoxied to the frame under the primer punch.

A proper fix from manufacturing is to have a high carbon steel button insert at the point where the bottom of the primer punch contacts the frame. To simplify manufacturing, it need not be screw-in, just a drop-in would be fine.