BYMONEK I never operated the A340-300 from JNB as it was not on our route structure but unless very light or a very smooth runway I did not derate as I found the A340 take off run most disconcerting with so much clatter and instrument panel bounce that I wanted to get airborne asap!!. Only once have I ever had to reduce thrust to keep below the 930 limit if my memory serves me right.A large number of our A340 flights were at 275 tons so full power was always required in any case.
Far too many Pilots IMHO derate without considering whether it is really appropriate.
Until I went on the A340 I had never operated with other Line Captains as even on the B767 on 13 hour sectors it was just the two of us! It is a real eye opener seeing how some Captains operate into places like SFO and LAX etc. I have cringed at times but also have picked up useful tips from others.