Yes, this is what we think Shawn Lane was doing. The idea is that you’re using an arm position which is sort of flat or even pronated a little, but you want to play pentatonics starting on a downstroke, like Eric Johnson. If you just moved the wrist sideways you wouldn’t be able to do this, because you wouldn’t have USX. You would either be trapped or even DSX. So to get USX you have to make a “dart throwing” motion toward the guitar body.
If you do this, and you use the more common index finger leading edge grip, the pickslant will be wrong. It will be 0 degrees (Andy Wood) or even UWPS (McLaughlin). This will give you garage spikes:
So so fix that, you need the trailing edge grip like Shawn. These things are not random, they all go to together and are more or less required.