noob question about increase effect of non damaging ailments

when i read the scorch description it says it can lower enemies elemental resistances up to 30%
is that the limit? what is the point of picking "increase effect of non damaging ailments" if it cant go further?

The effect is base on the damage you deal to the target.
The damage you have to deal to get the max effect is exponential.
With 100% effect if you had applied 15 reduce with your hit.
Then you reduce for 30%

I don't have the exact number but let say that to applied 15% you have to deal 25% of the max health of your target.
Then for 30% you have to deal 100% of your target health.

100% increase effect reduce the damage you need by 4 time (Again this is just an example I don't have the exact number but you can find them on the wiki)

the effect of a non-damaging ailment is based on the damage (ie how much % life you did as damage) you deal with a hit. normally it would be very difficult to hit a boss that would inflict 30% scorch since you won't be dealing 20% hp (dont know the exact numbers, just an example) damage to a boss with a single hit. if your hit would 10% scorch with a hit, with 50% increased effect of non-damaging ailments, the scorch would be 15%.

Now i get it. Ty guys.