A few more thoughts:
If for every stride added to the approach the jump gets longer, then the focus is instantaneous speed. The flying 10m split is just an average of the achieved speed. If you need 4 strides to cover 10m, then every stride added speed to your body. Thus the peak speed is greater than the measured one, f.e. 10m split gives 10.5 m/s you then may have been running for every stride: 10.35 / 10. 45 / 10.55 / 10.65. If we take f.e. Jonathan Edwards, he just used 16 strides for his 18m+ jumps and the peak speed for a 10m split was arround 10.9 m/s but I bet that in the last stride he was for sure at 11 m/s +++.