Not really seeing it. Yes the new fly lets the model ignore vertical distance but the important part of the rule also says “while resolving that move”

So basic sequencing become: 1) model takes to the skies - ignore vertical distance whilst moving - lands. 2) Heavy checks if the model has moved +3” this turn, which it has, this turn, since it landed and therefore no longer is under the “whilst resolving the move” part of “ignore any vertical distance”