Maybe implemented in flight planner. It would be VERY easy to implement the numerical moment arm calcs that show up, probably best in the flight planner. Perform simple subtraction of pounds of fuel per hour based upon stated burn in the profile, and indicate just where we are at takeoff and landing. And IF we have really goofed (and some planes with poor design exhibit this) and burned past max/min CG limits, turn something red in the flight planner and if we're in the air, turn something red as we start approaching limits.
Couple this with remaining fuel per leg in the flight planner (as so many have requested) and you'll have a more professional piece of software. Also very easy in software to implement.