After reading a about it, I think this is the best statement, but until today I was convinced that if u lower front pressure you'll decrease understeer:
Both are correct. Any deviation from optimum pressure will reduce grip on that end, so going either higher or lower from ideal will work. HOWEVER, if you lower the pressure, you are also softening the spring rate which leads to less understeer and now you have two factors working against each other.
One thing is clear tough, i was wrong.