I believe that the limits for the 412 are thus:
You can't use more than 81% above 105kts due to mast bending considerations
When you are below 105kts you can use up to 100%, but are then constrained by the 5 min eng limitation.
Have to say we regularly use up to 100% Tq when engaged in fire fighting, but then again we are also at MAUW with the bucket attached - intrestingly with ambient conditions of approx +30deg C the ITT is topping on twin limits at 100% Tq suggesting a well matched power train. I still wonder how much extra that 19% would give in the cruise though...