Great question about flushing and one that surely gets people excited. Me , Personally, I am in your camp. I'm not sure how much it really does to expell the minerals from the plant tissue....however, super over fertilized plants certainly have more minerals in their cell walls with increased turgor pressure and osmotic gradient (this is true for both organic and conventional). That being said, my teamates are much heavier smokers than I and they are very adamant about a 7+ day flush with plain water. They swear it makes a positive difference in the smoke and I don't argue with them. I am one that truly believes that success and sanity lie in "choosing your battles" and that is one I choose not to fight. It def doesn't hurt the plants unless we start the flush too early. We do this with organic cultivation by ceasing all microbial additives and top dress the last few weeks.
From what I gather, the common misperception is that flushing refers to an actual reverse flow of nutrient from the tissues and out the roots,... not purging the medium of excess nutes, and/or letting the plant burn through what reserves it can with mobile nutes it has stored... One of own old timers here coined the term "cleanse" as a better way of putting it-
-- save "flushing" for what it sounds more accurately applied to, medium flushing! Some low-no nute time also helps clean out the "pipes" (vascular system) and let residuals get metabolized...
Yup, that's my take too, if plants have been overloaded late into bloom then clearing the medium out some and letting the fans get tapped can help improve smoke quality. And w week running off what's in the pot (typically) isn't going to go sideways unless the plants was suffering beforehand.
Organics, almost never necessary unless a similar situation has happened (seen some horrid late feed snafu's! "tastes like batshit"
). .. I do taper way off the last couple weeks, mild inputs more on the K and S side to support good terp's production...
Several folks here swear up and down they have tried the same thing, flush vs no flush, apples-to-apples mush as possible, and report that most folks can't tell the difference, but that could be down to these good growers managing their nutes wisely,... So, the debate rages on!
... that said, I don't doubt that some savvy smokers can detect significant differences, but unless it's a very true apple-to-apple gig, there are plenty of variables to account for such differences....