I had a good friend in AUH, (average temperature above 30C), who flew the BN2 and always took off from AUH with no flap selected, I and another younger pilot asked him about this and he explained he had done all the sums, (he had them written down), and since the runway was so long it was the sensible thing to do as it stood him in much better stead were he to lose an engine. Friend and I followed suit but thank God we never lost an engine. Our mentor was an ex RAF wartime Beaufighter pilot and we took what he said very seriously.