Why does it matter to a students training what energy state the aircraft has once completing the maneuver?
It doesn't matter if it's just a single bird maneuver. It matters a lot if there are multiple birds in the air in a training fur ball. USAF wants to use the trainer to train pilots in high energy many-vs-many combat maneuvering. And in high energy defensive maneuvering. All that takes actual high performance, not make believe performance. And in this case, performance quite a bit beyond what the F-35 can do.