My thing is tiny plant ina giant pot, any time you feed a seedling, or an early veg plant , I will use a hand sprayer and spray water until I see the plant accept the mission. Otherwise all of your feed/water wash’s strait past the undeveloped root zone and settles at the bottom , a few feeds of that miscalculation.c and you now have a dead zone that no root will penetrate.
When you chop you’ll pull a root ball
that is nice, but on the top side only.
I'm not sure I agree with this.
I do agree that a tiny plant should not be in a giant pot. Autos are an exception, at least for me, as they don't like transplantation but, because they are autos and the time window limits their growth development, I usually don't plant them in anything larger than a 5 gallon pot for indoor growing so capillary action should get enough moisture into the root ball if I miss it in general.
What I don't agree with is saturating only in the immediate area that you think there are roots. Maybe I misunderstood the post but that's what I got from it. If you're in a solo then it doesn't matter but for large pots media saturation is much more important. Watering in only the immediate root ball area will certainly feed the plant what it needs and capillary action will spread some of that water to the outer perimeters of your media but whatever it was able to spread out will evaporate quickly limiting root growth.
One of the techniques I've used successfully is to water around the outer half of the media and not over the root ball itself. What happens when I do this is initial capillary action will lightly wet the soil over and around the root ball which will be taken up quickly by the immediate roots but once that water supply has been exhausted the hormones in the plant will signal it to look for more water by shooting new roots. Early root development, IME, is key to a bountiful harvest. Putting emphasis on early root development will power the rest of your plant down the road when it gets bigger and the foliage has outrun the roots access ability. The moment this happens the equilibrium in regard to root/ion accessibility vs plant maintenance will slow down foliage growth while it is trying to expand its root footprint to be able to increase the ion availability to be able to expand foliage growth.
You can also see this happen in nature. When rain falls on a plant the leaves usually direct the water that collects on them to water around the perimeter of the plant and not directly on top of the root ball itself. Different species handle water collection depending on water availability. Succulents are a good example of that.
In short, in seedling/early veg my focus is on root development. After a few weeks I start to transition that focus to still try and promote as much root growth as I can but start putting some of that focus on developing foliage now that I have the nutritional pipeline to do it. For me, this is a crucial time that will essentially dictate your end result so I spend more time setting up the plant so that I have a better chance at maximizing the plants potential when I'm ready to flower it.
Develop your root system and the foliage will follow. Bigger roots, bigger fruits.