Hello Cak,
That’s true. I saw that video. But I’m still on the side that feet up is safer. In a sim, if the instructor gives you a sudden power loss at low speed with Toga thrust on a narrow runway, there is a big chance you will end up in the grass with heels down as the autobrake will not kick in. With your feet up, you can control the aircraft and brake at the same time with no delay. But like you say, I don’t bother anyone if they have their feet up or down as Airbus is not 100% clear on that aspect.