Modification
Why don't Airbus introduce a suitable series of levers and rods from the thrust levers on the flight deck directly to the fuel control units on the engines.
Then they could have a third chap sit on the flight deck to help manage these levers and when not doing that could carry out walk rounds, a bit of down route engineering and seek out "interesting" places to take the crew too for refreshments...
Ditch FADEC and software and bring back flight engineers?