What if it needs to due to changing conditions? Where's the safety margin? Let's say it's a hot day, the air is dense, timing is a degree or 2 high, got some less than perfect gas, wastegate is holding a pound or 2 too much boost, etc. Then what? If for some reason you need the extra fuel, the pump won't be able to keep up and your pressure drops. I'm not saying to go crazy. Just plan/size things accordingly.