SpellTurnLeft and SpellTurnRight animation groups are unused
These unique animation groups go unused because they use a different naming format from other turning animation groups, so OpenMW fails to find them and fallbacks to normal generic turning animations in spellcasting stance. This generic animation is very different from the initial position of the character and can lead to prominent twitching while turning in spellcasting stance.
So they should be handled as a special case in character controller.