Post down here what your highest MSL has ever been. Recently I took the 777 to FL500 in solo server, but that doesn’t count. Put TS or ES server only. Anyways, I was cruising at FL460 in my Challenger 350 from MDW-DEN. I was getting good mileage up there. What about you?
FL450 in the 747-400 at a really light load. Believe it or not, the 747-400 is the only commercial airliner with a service ceiling of FL450. The A350, 787 and 747-8 have a service ceiling of FL430
They could’ve been referring to the replay space glitch where you have the app disconnect/go inactive and that can launch you upwards during the time the replay has registered the app as disconnected/inactive