The term flush, from what I gather, is misinterpreted sometimes. If you have toxicity, you "flush" 3X the pot, to clean her soil. When "flushing" before harvest, it is more of a water only thing. Giving her water only for the last 2 weeks will pull the last bit of food from the soil.
I have fed up until harvest and saw no difference in quality, taste, smell, tbh. That is highly debatable, though. The only reason I flush, is to not waste nutes, left in the plant.
That being said, if you see a good amount of amber on the buds, I would give her the axe. I wouldn't wait for her to dry. I wouldn't wait for a dark period. She will continue to ripen, slightly, during dry time.
These are my opinions, based on my limited experience. By all means, do what feels right.