This might be a stupid question, anyways: As far as I understand the two FCCs of any 737 in service do not control each other. Boeing now wants to change this, so that both FCCs are constantly checking each other. If so, won´t they have twice the workload, respectively: Won´t they need to be checked / serviced twice as often as before (twice the running time)?
There are so many more aspects which would scare me, just because they now need to change a proofed system. And changing things always inhibits the danger of new faults.