Help identifying picking method?

For the opening of Tramaine Jonathan’s cover of No Boundaries, I’m having trouble figuring out how he picks those 3nps sixes. Anyone able to tell? If I try to alternate pick the whole thing with DSX I can mostly get it with swiping but one of the string transitions doesn’t work. If I try 2WPS I can’t seem to get enough speed.

My guess is he’s achieving DBX with some kind of wrist helper motion, since his primary motion is definitely elbow.

Why does your method not work with one of the transitions? Can you post a video?

If I keep to a strict DSX motion with swiping used for the sixes, then there is one extra note at the beginning of the sequence that throws things off, unless I incorporate a hammer on, or use DBX to get through it. I tried watching the video several times at 0.25 speed and if he is using DBX then it is probably subtle.
So I guess if I don’t mind throwing in a hammer on I can make it work, and maybe I’ll just work on that.