LMSC
“On a normal V60 without drip assist, your method always has or had one or two centre pour(s) towards the end. How do you explain this, considering the above quote? 😊”
You can pour down the centre with a slower, more gentle pour with a kettle. Spiral pours are more agitating. I tend to pour in the centre whenever there is standing liquid over the bed, using a gooseneck.
With the Drip Assist the centre has bigger holes for a faster pour rate, the ring has a slower pour rate & the water drips very gently. So in both cases I’m aiming to reduce agitation as the brew progresses.