As an interest point, I have upgraded SYD - LHR using miles Y-J over the phone despite EF showing no D availability. I did have to get the lady on the phone to go through each day until she found one which she politely obliged to (flying on a flex+). EF was also only showing D available DXB - SYD on the way out but no availability MAN-DXB however I was able to get the upgrade on the phone.

I was tempted to gamble on the op-up having seen so many people get it on my flight out after I had spanked 62,500 points plus taxes however knowing my luck I would have ended up with no op-up and no on board upgrades available either!