Minotaur's "Rage" Ability

[David Ward]

Minotaur's Rage Trait says - "Your strength is temporarily increased by 10 when you have less than 20% health remaining."

Is there a way to change the % here? How could it be made so that the strength bonus applies when there is, say, less than 40% health remaining instead? 20% seemed a bit low in Grimrock 2. I found this trait to be a very rare (if even noticeable) occurrence and wasn't really worth using up a trait. But at 40% or so, it very could be.