The hollow arpeggios from Well Dressed Guitar form the core of my picking practice.
I’m about 5% off his pace once fully warmed up.
This routine has helped every other alternate picking lick in my wheelhouse.
I often accidentally double pick the lowest note of the arpeggio in between the last upstroke and the initial downstroke of the next arpeggio.
Interestingly Steve does this a lot too. You can hear it on the arpeggios at the end of the song that are fretted on the D, G and B string. He often double strikes the D string.
I don’t have a solution yet at full speed!
I found quite a lot of speed came from using wrist flexion or extension for one stroke and deviation for the next so I use different muscles for each stroke whilst creating a double escape motion.
I can do the same speed regardless of anchor point, pick slant and whether or not I use 2 or 3 finger grip as long as I can stay relaxed.
Trying to achieve an escape motion with wrist rotation slowed me down so I avoid that.