What. I've done side by sides a hundred times, With general hydroponics if I run the micro all the way without flushing I can taste the nasty micro in the bud, and ppm's never go above 1200.
I don't flush for two weeks, but also run a DIY aero w/ ez clone sprayers. What I do is cut the micro and grow out the last two weeks using only the bloom, liquid cool bloom, floranectar, and florablend. Then I rinse with plain water for 3-5 days sometimes seven. But that is well water so it still has trace elements in it.
This is only my preference and I am not arguing, I just saying in my experience dro needs a flushing if you use chemical smelling ferties, soil should never be flushed because you should never put chemical fertie in soil to begin with. Cheers and smoke what'cha got.