Don't forget up to V1-6 kts the aircraft will flash ENGINE FAIL on the PFD and shout it at you too.
If you read the FCOM SP Adverse weather it states F20 provides the best performance in windshear conditions providing the departure is not obstacle or climb gradient limited. It also suggests departing with F15 as a compromise as performance is almost as good. Which the limited differences between the above analyses bears out.