Not entirely sure what tag to give this bug because none of them seemed to fit, but I digress.
Molt Augmented's description says that it gives +0.24% Ability Strength on kill, and that it stacks up to x250. It should hit +60% Ability Strength at x250, but seems to fall short.
I'm using Kullervo and modding him with Fleeting Expertise, Intensify and Transient Fortitude to get my Ability Strength to exactly 140%, so that when I max out Molt Augmented that number should reach 200%, but looking at the abilities while in-game they all fall short. On the stat screen, Wrathful Advance reaches 399% Melee Critical Chance, Recompense reaches 19,999.96 Overguard, Collective Curse reaches 99% Damage Redirection and Storm of Ukko reaches 4,999.99 Damage / Second.
Uploaded a video so you can see for yourselves:
