I think that a point that seems to have been missed, and perhaps what the original poster was alluding to is confusion with the "
Roll-On" Takeoff (not Rolling). That is, a Takeoff where the aircraft enters the runway at the nominal Takeoff commencement point already rolling with residual speed from the taxy.
For a 90 degree or 180 degree turn to line-up, this is obviously not practical or safe, but there are many Runway entry points such as Brisbane 19 and the new Singapore 20C where significant taxy speed can safely be maintained up to the SOT (Start of Takeoff) point where Takeoff Thrust / Power is then applied whilst still rolling.
I recall working on one Douglas jet aircraft where the AFM stated that the Maximum Achievable Takeoff Weights were (1) Roll-On Takeoff, (2) Standing Start, and (3) Rolling Takeoff in that descending order. The AFM went on to explain that a properly executed
Roll-On Takeoff was one where the aircraft had a minimum speed of 10 knots at the normal SOT. In these circumstances Standing Start Takeoff limiting weights were permissible, whilst better than Standing Start actual performance could be expected.
Regards,
Old Smokey