Originally Posted by eightblack

From my own experience, booking FLEX vs SAVER wont impact of affect your op-up availability. I only book Flex because I hate the whole half rate tier miles and reward miles. Ok, I may not "need" them, but it's beside the point. And many times, the differential between the Flex and Saver fare is minimal (on the routes I fly)

If I was you, and I know this would have extended your trip, I would have gone DXB-SIN-MEL. You used miles to handle the LHR to DXB leg, you may have struggled to clear the DXB-SIN leg (very elite heavy) but you would have been in a very good position op-up wise between SIN and MEL.