You’ve been waiting for it, and FlightSimSoft did it : TOPCAT now supports the PMDG 777-200LR and Freighter version in its last version 2.74.
It’s specified that it is working with PMDG as the takeoff performance calculation tool writes in your “aircraft.cfg” file to apply the weight and balance changes you set.
FlightSimSoft team is also the developer of Professional Flight Planner X.
