Flush for a good reason -- a toxicity is ongoing is a good reason to flush.
Flushing at end of harvest is a myth... perpetuated by those that don't want to admit they've been wrong for decades. If you know a little history, this is a common behaviour when the smart ppl start coming in and clearing things up... just as those GM/owners who cried about sabermetrics in baseball only caused their teams to fall further behind and now have all adapted to a better way of evaluation... fwiw baseball sabermetrics are troglodyte in nature at times, too.
Flushing before harvest causes no change in mineral content of your buds. -- proveable with proper equipment, and has been... this isn't a typical "90% of initial studies are false" becuase this is far simple context of pass/fail type result... either it stores and easily measured molecule or it does not.. in this case, it in no way impacts the minerals or what constitues a bud.. therefore, it does not reduce "salts" in the buds.
Blind taste tests show ppl clearly cannot distinguish between a flushed harvest and a non-flushed harvest.
This is the difference between a bunch of hooligans growing in their basement, like me and maybe you, and someone with a lab and resourecs to flesh this stuff out. i don't own 0k pieces of lab equipment to ensure i've extracted each individual molecule that makes up a bud, but labs can.
it's easy to be fooled by what we see with numerous factors changing in our grows.. sometimes during a grow. When someone does a controlled study, it's no guarantee they are right, but i'd trust the effort over some group of ppl that never took an advanced biology class or any science for that matter... it's not something you can monkery-see, monkey-do often... it takes a building of knoweldge over time that you just can't pull out of your ass with no effort. always read up on their methodology.. can easily see the "phd" that cannot do their jobs well, lol. they too lack rational logic often in an effort to prove themselves correct, but at least it is self-correcting.. ppl will call their bullshit and we'll move on.