Intellect, Resolve and Duration Times in TB

[lucasolt]

I was thinking about duration times in TB, and it would seems right now that having 14 int or resolve is optimal, because of rounding down.
A way to deal with this, I think, is instead of rounding down when the number is not "full", you could make the decimal places a percentage chance of an extra round. For example:

15 seconds duration spell

You have 20 intellect which means an extra 50% duration time.
15x1,5=22,5 seconds

In turn based, right now, it would translate to 3 turns. 22,5/6 = 3,75.
Instead of being 3 turns, it could have a 75% chance of being 4 turns, and 25% of being 3

I think it would be a simple but fair solution
What do you guys think?