Lyman, you are confusing the right hand and the left hand. The Phantom was designed long before in St Louis by McDonnell only. The MD-11 in Long Beach 20+ years later using a lot of Douglas DC-10 technology.
In any case, substantive modifications to the aircraft in that part of the airframe are likely to cost really big $$$ and cannot be economically justified.
The MD-11 could probably also use a "bounce" warning system with a verbal annunciation of the condition. If it is that hard to tell (in time) that the aircraft has transitioned back to airborne after a firm landing, then something should warn the guys flying. (More systems geek thoughts.
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