Afraid I have to disagree here Over the last 30 years I have flushed, and I have not flushed, and in my experience it does not make the difference you say if you cure your weed properly.
The worst weed I have smoked was from my early days when I just put plants in compost and watered them (no feeds) which was like giving them a 6 week flush. That weed did not burn from the lack of elements inside it to combust properly, phosphorous for example.
That weed went black, would not stay lit, and left black charcoal instead of ash. When I upped (started) my feeds, it smoked OK.
My opinion is that when you flush in hydro you are actually doing a partial light cure, which makes the difference you detect.
I have given some of my unflushed (but cured) weed to people who flush (and say the same as you that flushing is important and they did a 3 week flush) and when smoked side by side they rated my unflushed (but cured) weed as better quality than their flushed weed. They even asked me what I did to my weed to make it better than theirs ( we grow the same clone) as they wanted the quality I was getting...
This article is interesting and makes some good points. To flush or not to flush
Also this one
If you find any articles that even slightly question the effectiveness of flushing, hydro or soil, then you will be looking at an article that does not find that flushing does what is claimed.
Just my opinion...
might start a thread to see what other peeps think.