I don't mean to step on anybodies toes and I'll be the first to admit that I am not super experienced and also that what you guys are saying does make sense to me. I'd just like to offer what I think flushings intended purpose is, to me:
The IDEAL goal of flushing is to time it perfectly with your harvest. For instance... you want them to JUST run out of nutrients right when you pluck 'em. This way they don't starve in anyway; they're more or less just ready for another feeding. You want to minimize the amount of stored nutrients within the plant material that photosynthesis hasn't yet used, if that makes sense. Remember that the plant will use its energy for the buds rather than fan leaf and other leaf, so deficiencies in leaves do not necessarily indicate that the buds themselves are starving. So in conclusion, the goal is to smoke buds that were never starved, but also don't contain excess and unprocessed nutrients. Just my two cents.