If you search YouTube for V60 brewing videos and guides you’ll find about three billion different ones. Some with agitation, some without; pouring fast, in the middle, making circles; 40-60 or 30-70 or whatnot.
I always think to myself that they’re mostly just fluff.
It all depends on grind size and temperature. Doesn’t matter how you pour (well, within limits I would think) as long as you get your temps and grind right for the pouring technique you’ve chosen.
Admittedly, I haven’t tried a ton of different ones, maybe three or four. But this is the feeling what I’ve got.
Maybe there are some edge cases, like Ethiopian coffees being more prone to clogging the filter so less agitation might be a good idea.
It’s easier to be more consistent with a immersion brewing method compared to percolation. The only variable in immersion brewing would be grind size and water temperature.
This has been my experience. I use the hario switch and a had grinder. I’m able to make pretty consistent coffee from day to day. Dead simple to use as well.
I use Hario switch too but manually brewing like a V60, so I keep the flow off during blooming (add like 2x of grind weight in water and wait for 30secish) and then do two pours, about half and half of my entire batch.