First of all, your fuel summation unit is often less accurate than 500 kg., especially on ground. Do not waste fuel. If you have to leave the gate with max. Ramp fuel, this also means you are dispatching with min. Flight plan fuel for your flight...
Secondly, some here do need to get into the books more and get an understanding on how carbon brakes work.
You will NOT overheat brakes when you are stationery and add thrust. You need FRICTION for brakes to heat up. Prolonged taxi is therefore more harmful than holding with thrust.
From all options, the best is to just ask to hold for a couple of minutes and burn the bloody 500 kg. If you insist. But do understand that ALL values on your loadsheet are estimates, and NOT absolute numbers, as is the onboard fuel displayed.
Ps. On B744, you need to look into the brake cooling schedule if your brakes temps. Are over 2 units. Nothing in the books on what the max. Brake units are for take-off but you do have to realize this. On Widebody, brake temp. Does rise very quickly.