Hey Rado, it's way early for me, so I'm just going to riff a bit.
I've seen a weight versus quality relationship in most of my grows. There's lot of ways to break that down though, and no two grows are the same. Generally, in soil, the most important thing is to not have too much of anything in the soil, and to get IN as much oxygen as possible, with proper watering, so that you cycle the plant like it wants. Having too much of anything, and overwatering cause the most problems. I'd rather run them on the deficient and drier side if I had a choice. With all of that said, if done right, with most strains, there really isn't that much of a difference in quality, when you come in near the top of your yield potential. I've found a few exceptions, but it's more likely that I'm not giving them what they want.
I am a big believer in pH. A real believer. I believe that if you don't add nutes, you can rely on the soil to slowly adapt, acclimate, and then control the pH in the immediate rhizosphere, if your inputs are within a certain range. But, if you are adding anything to the water, that the plant is waiting for, I would pH it to 6.3 in soil, every time. Using organics only, I think you can go lower without too much issue, but not too much higher. I'd have to defer to PJ on that, as I use nutrients in addition to the organcs already in the soil. Anyway, it only takes a minute or two, and once you know your mixes, and water, you know what your pH will be before you even start. I don't measure anymore, but I know where it will be.
For yield in training - I like to top once, and early. The plant will sit down in it's pot, and thicken. Thick branches, produce so much better. That's also what the crushing does. The injury sends hormones to down from the site, so that the support below, is thicker and stronger. I do this with a lighter touch than many. I don't break the outer skin usually. I just roll the stem, just a node or two below the top, where I can get my fingers in, and squeeze, till I hear/feel it crush a little. You might see a little sap stain the outer skin. You can really snap them over, and supercrop them too. Depends on what you want, and if you're running out of height. I do this from about week 2 in Veg, although when they are young, I just pinch, rather than crush. Hit em once and then let them heal. Repeat until you are happy with them. A blowing fan will also thicken them up.
Adding benes like bacteria and fungi, and keeping them watered correctly, do amazing things to roots. When you combine all of that with an acceptable environment, and enough light, yield should be there. I aim to get a zip per gallon of soil. Doesn't always work though. With short Veg plants - I've got over 8 in a 3, and under 2 in a 5, so there's that too.
Good genetics are as important as anything else too. I'm looking forward to seeing your experiment, and all the rest. Best to you both