EDIT 2
Ok it looks like the StrengthIncreaseOnExp is actually not being used to calculate mellee damage. I was playing about with some values and found that even with stupid values like:
A Level 3 Bile Demon would, without fail, have to hit a Braced Door 10 times to break it (I tested on Deeper Dungeon's Kanasko as a quick test) unless the DamageIncreaseOnExp was upped (In which case the damage would scale regardless of the value of StrengthIncreaseOnExp). As such, the mellee damage would only increase by 20% instead of the default 35%; Percentage of creature damage increase for every experience level
DamageIncreaseOnExp = 0
...
; Percentage of creature strength increase for every experience level
StrengthIncreaseOnExp = 2000
Is this intentional? Isn't the mellee attack meant to use the base strength in its calculations?
Let me know if I should raise this as a bug