50EX can't go straight to FL410 following a max weight takeoff?
Yes it can. G200 just likes slamming the 731's on almost all of the Falcon's.
Now that said, yeah if you were in a condition where you had to have the heats on going through the HIGH 30's the climb rate does peter out but I've rarely had trouble getting to 410.
Doing .82m with the heats on at FL410 is an entirely different matter.