He posted this on Youtube, what do you think?
I play like that too. I use a small movement at the fingertips for making some string changes, although I haven´t analyzed it closely.
Like he says, I just do it by feeling because it feels more natural to me than having the fingers always at the same position.
It’s good to know that even people like R. Graham who have played countless hours, still tweak and play around with different mechanics.
thats the value of super precise motions though (consistent picking depth etc.) He gets results from tiny finger movements