Is the legendary effect free fall a vanilla effect?

I have a mod that makes me able to put any ledendary effect on anything. Certain ones show up randomly and some dissappear. It's kinda like minecraft enchanting tbh. To the point tho i've never seen a freefall ledendary leg piece. Been playin the game since drop. I have this mod but very rarely do i use it for armour. I use it mostly for weapons. Last time i even messed with leg armour i only saw acrobats as 50% off fall damage.