Neptunus Rex.
I'm afraid you're showing your ignorance.
In formation pram pushing a flat display is one where they let the air out of the tyres to give better traction on wet grass under high G conditions.
Now if your talking about the Dead Sparrows display, that was pretty flat.
Seriously, the best display of the day was by Ian Gallagher in the vintage Lo100 glider. Finished off with a low inverted pass with an even lower roll out. I believe the display director was so impressed he sent for Ian ten seconds after he landed.