you have, like others here, failed to recognise that the gross risk
that may well be so .. however, my comment was directed to the individual takeoff being considered in isolation .. at the end of the day, we have risks all around .. and, as one of our PPRuNe colleagues who specialised in risk assessment (and, unfortunately, is no longer with us) would opine .. the numbers are rubbery so the discipline has to be high.
fitted with vortex generators to increase MTOW but dont have
those I have examined in years past addressed the necessaries as part of the STC process .. I would be a little surprised to see an STC which didn't .. not to say that couldn't be the case ..