Ben There
Max landing weight in kilos for the B747-400 is 285,763kgs, at this weight max rate of descent at touchdown from Boeing is apparently 600fpm. The max take-off weight for most pax -400s is 397,893kgs - the max R.O.D. at touchdown at this weight is 360fpm. Such a rate of descent would be considered a"hard landing". Overweight landings up to max take-off weight are now not restricted to emergencies, but are (apparently) an option to the pilot for other considerations. If you can get airborne at max weight, then in most circumstances, you should be able to land on the same runway, without the need to dump fuel. It is an option, not a directive! In my opinion, it would need very careful consideration and a bit of nerve to do so.