After a few years of experimenting I can't claim to be an expert so this is strictly an opinion. I brew with a certain target range of brew time, keeping the ratio (15g coffee, 250g of water) the same, varying the pouring structure, grind and temperature. I brew with an Origami and Kalita papers.

I think you could say the 4:6 pour structure can give a more "crisp" cup. Also thinner, sometimes to the point of being bland to my tastes. But it depends. What happens, at least for me, is that the latter pours become increasingly slow. So if you keep the water temperature constant the last two pours IMHO tend to extract too much and can lead to bitterness. This is true to probably all the techniques out there so I tend to let the water just cool off while I brew, extracting less of the final phase.

If I want a more round, full, rich and sweet cup (my usual preference) I would make something along the lines of 50+100+100, or 100+100+50 structure, sometimes even a 125+125, depending on the coffee at hand. And always a declining temperature. These structures need a finer grind which also should contribute to a sweeter and fuller brew.

My working theory is that while there is water in the slurry, there is also immersion style infusion going on, not just percolation. The effect is similar even in espresso when doing long preinfusion or blooming profile, yielding a more rounded and mellow result. A frenchpress / full immersion would be the extreme case then where in fact you get a very "round" and balanced result.

So, putting the theory into use (and I'm quite confused still on how and when ) I would apply more or less water in any which part of the brew.

Sort of related to this you could check the new Kasuya method with the switch if you didn't already:
Kasuya's new "Hybrid" Hario Switch method, also works on Clever dripper

The above recipe plays with the same ideas I mentioned; trying to extract more at the first part (higher temperature, more pours, more percolation) and then less at the latter with cooler water and more immersion infusion.

Final note: I don't think there are definite answers to anything in pour over brewing. It's all a very interesting and satisfying, sometimes frustrating, mess.

It would seem that the more water you dump into the brewer at once, the more you 'bathe' the coffee grounds in water rather than 'shower' them with water, therefore the more your brew tends towards immersion rather than percolation (though still obviously under the umbrella term of 'percolation' since you're using a drip brewer).

The more a brew tends towards immersion rather than percolation, the more full-bodied it is as a general rule. The rule breaks when you add pressure into the equation, which is why espresso is a percolation method yet produces the most full-bodied type of coffee of all.

The 4:6 method relies on a multitude of smaller pours, therefore is more towards the percolation side of the continuum than the Hoffmann method (which is more towards the immersion side). I guess it would therefore make sense if it produced crisper, more acidic brews with a thinner body.

However, what is interesting is that the osmotic flow method could be argued to be on the extreme percolation side of the continuum since you are doing a very slow controlled pour and never really letting the water level rise above the height of the bed of coffee grounds. Yet, the osmotic flow method is thought to produce very full-bodied cups that are lacking in crispness and acidity. This seems to go against the general rule - but is perhaps because the grind size recommended is radically different (much coarser).

Love the 4:6. I've got 6 different pour over devices and have used them all extensively but always come back to the V60 using the Tetsu method as my favorite. I do 5x60g pours with 20g of coffee coarsely ground with SSP MP. I do the bloom direct from the gooseneck to agitate and give it around 35s. Then I switch to melodrip to do the rest of the pours. I end up having complete draw down around the 3minute mark.

I'm not sure how hard it is since I started on a V60. I remember there being a learning curve. It is funny to try something like the April dripper and be like, "that's all I have to do?"