In a way, yes, I have done a side by side. I got heavy into defoliating when I grew indoors in my closet illegally back in the 00s in the midwest. I was running some clones, and I was always real nervous about fan leaf removal because of the hubbubb about the importance of fan leaves. I was growing with a MH for veg, and a SonAgro/HPS for flower. In the summer, I always had heat and humidity issues, and the plants took up a ton of water -- especially during the stretch. Trimming was also a lot of work, and even though I was an experienced grower utilizing other training methods (FIM, topping, and ESPECIALLY supercropping), I would end up with quite a bit of larf and foxtails. It sure was pretty looking at all those fan leaves, though! One day I decided to try removing most of the big fan leaves just before flower to combat the humidity and crowding from all the new growth that my training methods brought, and it didn't hurt the plants at all. I noticed a significant improvement in the bud structure of the lower growth at harvest. It also cut down on the watering needs and lowered the reading on the hygrometer. The next run with the same clone, I did a heavy lollipop and defol a few days before 12/12 flip, and my results were even better, and that's how I grew from then on. It was many moons before schwazzing was a term, but, then again, I wasn't quite as extreme as a full schwazze back then, but I removed a lot, and was pretty quick to yank fan leaves at will throughout flower.
I'm no scientist, and don't claim to be, so I can only speculate why it works.
Another story that I'll share is one I remember reading from a grower that left his indoor grow on autopilot for a few days without checking during flower, and came back fo find his plants had outgrown his light height. He said the buds above the light discharge were real underdeveloped, even if the fan leaves were right under the light. The general consensus was always that the fan leaves under each cola are what transpire and photosynthesize for bud growth, but clearly this wasn't the case. There is indeed chlorophyll in buds and sugar leaves, and getting lots of air and lots of good light on all the buds simply makes them grow better.
As for the nutes, I don't really use them in my living soil mix, at least not directly. It's the soil biome that I feed. I'll do various kelp and aloe teas throughout the grow, particularly to combat heat stress, as well as some compost and carb teas, some cyto during veg; but I pretty much just use good water, don't worry about any flushing at the end, and usually the fade takes care of itself. A good fade really brings out those terps, and drastically improves the smoke-ability. I don't like seeing a lot of green close to harvest, and I the last thing I want to see close to the chop is curling leaf edges or any signs of burn, regardless of what the buds look like!
