I apologize. Yes, "Foot", not "Leg".
Also, according to NVTF's author:
Make sure that your in-game framerate is capped below 120 FPS. Better use some fps counter to double check if it really is below 120.
That is a trade off between player foot dynamic placement efficiency and the absence of foot bouncing glitches for NPCs. It eliminates NPCs bouncing glitches almost entirely, but also makes player dynamic foot placement work slightly worse.
Set these lines in [FootIK] section using either "FalloutPrefs.ini" or "FalloutCustom.ini" to the following values:
bFootIK = 0
Try capping your framerate to something lower than 120 fps.