New hammer hardness

The new hammer global slider is not specifically documented , but based on what I hear and given it varies between (-1 and +1) I suppose it transforms the values of each by individual hardnesses ( piano , mezzo , forte) by percentage , negative or positive . So if you position the cursor on +0.2 all individual values are increased by 20% . Upper values of each individual hardness parameters are limited to max = 2 and min =0.  Can someone confirm I am correct ( or wrong) ?