While I am in the ‘no flush’ camp, the study I have seen found no difference in yield between flushed and unflushed. In fact, they found no differences at all.
My opinion is that you can flush if you like, or not flush if you like, it does not matter as long as you cure. The harsh taste is from chlorophyll and you can reduce this either when the plant is alive, or after you cut it. I prefer the term ‘live curing’ as it more accurately reflects the actual process that occurs.
For people who want to smoke their cannabis as soon as it is dry, live curing is essential because it is essential to cure your cannabis at some point. If you are patient, dry curing IMO gives a better final product.
People who understand the life cycle of a cannabis plant know that it automatically stops taking in food during senescence so reducing the nutrient strength to stop the plant taking up nutrients is pointless because it is a process that will happen anyway.
People who understand how the root functions know that you cannot pull nutrients the ‘wrong way’ so it is simply not possible to leach nutrients from the plant by changing the strength of the solution at the root surface. Sure you clean your medium, but you do not remove nutrients from the plant via the roots.
People who understand curing, the processes that occur, why it is important, and the effects it has on the final product know that you can get smooth smoking cannabis without a live cure as long as you do a dry cure. Both remove chlorophyll and so both result in a smooth smoke. What is essential is to cure at some point to remove the harsh taste from chlorophyll.
I will add a data point for the people who have said about terpene production being aided by micronutrients in later flower as other people who have grown the same clones as me failed to get as complete an expression of the potential of the plant, aroma-wise, when they used the same brand of nutrient, in the same type of system (NFT) under the same lights (HPS), with the only difference being a flush. They did a (to my mind excessive) three-week flush, and whilst they also attained the same yield they did so with 33% more space, 33% extra light, and weeks more time. My view is that, because they had their plants in no nutrients for 1/3 of their flowering time, they impinged on the vital nutrient uptake during a critical time thereby reducing the quality and yield of their final product. Most people who flush for less than 10 days IMO would not see this drastic reduction, the plant has enough reserves to last for roughly that long.
They were obsessive about monitoring their plants and their environment was almost perfect, same as mine. They always asked me what I did to get a better result than them yet never believed that it was the lack of flushing. To them, it was too counterintuitive and they could not let go of their certainty they were doing the right thing.
EDIT :
To anyone on either side who says there is no evidence either way, this is now no longer the case, although it used to be in the past. Now that Cannabis is legal in some places, that means it is legal to study for your post graduate, or whatever course you are on where it might be relevent.
This means studies are slowly coming out. Scientific studies that actually look at what remains in the cells of the plant. It is no longer ‘stoner science’.
The levels on nutrients are not lowered by a live cure, or flush. What is lowered is chlorophyll. The question of whether nutrient levels reduce is not in question any more and they do not reduce.
Of course, there will be a taste difference between cured and uncured cannabis but that is not comparing apples to apples. The actual test should be between properly cured cannabis and properly cured cannabis with the only difference compared being live cure, or dry cure.