In case anyone was wondering, the reduced damage acrobat mod (-50% falling dmg) is additive rather than multiplicative. As in, with them on you can fall from any height.
Multiplicative resistance: 100dmg * 0.50 * 0.50 = 25dmg
Additive resistance: 100 dmg - 100dmg * (0.50 + 0.50) = 0dmg...