Pool,
the OPT/LPC etc software will optimise performance figures based on the greatest margin over the most limiting segment eg. field length/second segment etc. That is of course why "Optimum" is the default. If you have reason to want another flap setting etc - you force the OPT/LPC to use that, and it will spit out most likely a higher thrust setting requirement or even a MTOW weight limit if performance in that limiting segment becomes effected.
The technique that ensures all SOPs are covered is to use the optimum unless directed to use otherwise by FCOM supplementary procedures eg. possible windshear. This was the case in the current Phase 2. If you just went "optimum" in this case, you would have been marked down for it (there is no "Windshear" button on the LPC/OPT
!!!
So if you want to 'stack the odds in your favour' - (say you think the runway has rubber residue or your tyres ain't so great for example), and still follow the SOPs, then do all the figures as per correct weights - use the correct speeds, but bump the power up a little either when entering the flex (airbus/boeing) or indeed on the boeing after you've reached 80 knots on the roll. The performance figures are still valid (reference Vmcg, Vmca which are derived using TOGA) but you will reach the speeds earlier and climb at a greater rate.
The company will never send you a bill for using higher thrust settings than required, but have a reason to do so as it does effect engine life hence $$$.
My two cents worth!
