Don't bother flushing. More and more research is showing that flushing isn't beneficial and doesn't actually do anything to the quality of the buds or to the nutrient concentration in the buds.
One of the newest studies even did a taste test and more people preferred the unflushed bud over the flushed buds.
https://www.rxgreentechnologies.com/rxgt_trials/flushing-trial/
What seems to be the best option is tapering down your nutes for the last portion of your grow. I typically start tapering down my nutes a little every time I mix them, starting when I think I'm 2 weeks out from harvest. I usually am feeding a 50% dose by the end of the grow.
Doing it this way you save some money and are still providing the plants with enough nutes to do what they need to do. I've also never had anyone that has tried my weed complain about the quality or tell me they could tell it was unflushed without me explicitly telling them.
The dry and cure are what hves the biggest effect on the quality of the weed once it is done growing. If you dry too fast, too much, or just don't cure properly, in general, you will wind up with bad-tasting harsh weed that everyone attributes to nutrients in the bud when that's just not the case at all.
Good luck and I hope this answer helps you make an informed decision!