Chinese carriers don’t care about fuel saving. Being safe at all cost is their top priority. Knowing how picky they are if you do an overweight landing (>1.79g is considered an hard landing in my outfit) ;I would just hold until below max landing weight. Did they hold with gears up to be in the air for so long? Holding at green dot speed with gears down on A320 CEO you will burn over 4T/hour