I thought that performance calculations considered takeoff thrust at Brakes release and not at any particular speed
From a 737 FCTM: "A rolling take off procedure is recommended for setting take off thrust. It expedites the take off and reduces the risk of foreign object damage or engine surge/stall due to a tailwind or crosswind. Flight test and analysis prove that the change in take off roll distance due to the rolling take off procedure is negligable when ccompared to a standing take off. Brakes are not normally held with thrust above idle unless a static run-up in icing concditions is required".
Full power on the brakes is not used to calculate take off performance in most jet airliners except on some piston engine aircraft.