Wondering when to flush this girl and cut the nute...

Honestly, I would skip the flush. I've never flushed a grow I've done and my bud quality came out the same as my buddy that used to flush. Now he no longer flushes and has noticed slightly better yields. jst think about what happens when you flush. The plant starts cannibalizing nutrients from its leaves and depositing them in the buds. So even if you don't feed the plant it is still putting nutrients into the buds to make them grow. There was a study done last year that even proved this. Unfortunately, I don't have the link anymore, but their end results were less than 5% average difference in total nute content between flushed and unflushed buds. That's nearly nothing, and comes out to less than 1% of each individual nute. If your biggest concern is a high-quality smooth smoke then make sure you dry and cure them properly. Chlorophyl is the reason for harsh smoke, not nutes. The dry and cure is the biggest part to breaking down chlorophyll and achieving a smooth smoke. Dry slowly so it takes 7-10 days for the buds to dry. When you jar them throw in a humidity monitor to keep tabs. You want the humidity in the jars to be between 62% and 58%. If they are over 62% but under 70% burp the jars for an hour or 2 every day until it hits 62%. Once at 62% just burp for a min or 2 every day to introduce fresh air to aid in the cure. If the buds get too dry they stop curing and the chlorophyl will no longer break down.