I'll be honest, I'm not sure if you are trying to patronize me or just being genuinely inquisitive, so I will side on the error of grace.
I start waning N right after transition, on average I cut all N out about three to four weeks before chop to make the plant use up it's stored N.
Knowing that nutrient elements make up about 8-10% of the dried matter (bud) and N levels can be as high as 20,000ppm, I do this to leave the finished product makeup more concentrated in H, O and C. This gives the buds a better taste, I also cut back K in the last two weeks for the same reason.
I'm not saying this is the only or best way to finish a plant, it just works very well for me and my customers.