that's what it's all about right here ! ^^
question master grower dude ..... is it true the plant stops making sugar altogether in the last 2 weeks, and uses whats stored.
When you're growing organically, the goal is to create a balanced, living soil. One with everything your plant might need. The microherd and the roots work together, more exudates from the rootzone let the microbes know what the plant needs and the microbes provide. You can't really flush out microbes, you can drown or dry them out to death if you're feeling cruel lol.
And a balanced soil like this is made with castings, compost, and insoluble amendments. All slow release fertilizers, and insoluble so you can't really flush them out. And you're reusing your soil so you don't want to get rid of all the hard work you did making a healthy balanced soil! And a lot of those amendments take so long to break down you don't even see those benefits until after a few grows.
Flushing is a synthetic grow thing, if not properly flushed its the fertilizers you're tasting, not the unused sugars in the plant...ish
Amendments can affect the taste in organic gardening too...using fish bone meal or fish meal tends to bring out plants natural "funk" smell. Overfertilizing (especially with guano) can give you too much of the usually appreciated earthy flavor.
Let me point out that while flushing isn't a thing for organic gardeners...if you're using water soluble organic fertilizers (guano, fish hydrolysate), I would back off any additional ferts the last couple weeks just because it will allow the plant to produce it's most natural flavors.
Think of it like this...a force fed chicken or cow might have more weight on them when they go to market. But the meat will be fatty and not as flavorful as chickens or cows allowed to graze on their own and eat when they need to.