Read about the AF447 Rio-Paris crash. Input stick averaging?? That's a huge design mistake which contributed to the crash and AFAIK is still here..

What’s the alternative? I think averaging with a dual input alert is a pretty good solution. Otherwise you need to find a solution to transition from one stick to the other. You can’t just switch sticks with the press of a button because the input could jump from elevator up directly to elevator down for example.