I guess my question is...what is the definition of "too much"? Any nute will make your herb taste harsh if you overload your plants with it...especially if it causes burns. Also, the flush at the end of your cycle can remedy most of the overload of nutes. I am not so sure phosphorous is anymore responsible for harsh weed than the other nutes.
I am pretty sure an over-abundance of any nutes will make the buds harsh. The clorophyll in uncured buds will make your smoke harsh too. If you have a decent soil mix you shouldn't need to feed at all during the last 10-14 days and let the plants use whatever is left in the soil.