We were instructed to keep heels on the floor during take-off, (Airbus FBW), i.e. steer with our toes on the bottom of the pedals. This was I believe to avoid accidentally disconnecting the autobrake during an RTO.
On approach to land, the Airbus conducts a brake test, so it checks there are no locked brakes before landing.
What circumstances would require one to apply differential braking on the point of touchdown? (given that you will be well above Vmcg at this point).