Whilst I absolutely agree with those comments guarding against "rushing around at low altitudes uneccessarily" there maybe times when it is actually necessary and so is worth thinking about from time to time on how this could be achieved safely.
Just change the uncontrollable engine fire scenario to one of dense uncontrollable smoke in the F/D or cabin and the required justification may be there and even a 20kt tail wind may be worth considering.
Also worth noting, from the FSF bulletin linked above:
In the case of -WE (BOAC 707 LHR) the No. 2 engine, together with part of its pylon, became detached about 1.5 minutes after the start of the fire BUT this was attributed to the fuel valve not being closed as required by the drill (QRH or recall equivalent). So again the comments about ensuring drills are correctly completed in addition to expediting are spot on.